This happens on the initial start of the track:

[08-06-15 09:34:39.8506] Slim::Player::Source::playmode (309) 00:04:20:10:01:57: Switching to mode stop from play
[08-06-15 09:34:39.8515] Slim::Player::Source::playmode (412) 00:04:20:10:01:57 New play mode: stop
[08-06-15 09:34:39.8518] Slim::Player::Source::playmode (461) 00:04:20:10:01:57: Stopping and clearing out old chunks
[08-06-15 09:34:39.8536] Slim::Player::Source::resetSong (1727) Resetting song buffer.
[08-06-15 09:34:39.8545] Slim::Player::Source::resetSongQueue (1556) Resetting song queue
[08-06-15 09:34:39.8548] Slim::Player::Source::resetSongQueue (1566) Song queue is now 0
[08-06-15 09:34:39.8554] Slim::Player::Source::playmode (581) 00:04:20:10:01:57: Current playmode: stop
[08-06-15 09:34:39.8557] Slim::Player::Source::jumpto (1294) Jumping to 9
[08-06-15 09:34:39.8560] Slim::Player::Source::streamingSongIndex (1482) Adding song index 9 to song queue
[08-06-15 09:34:39.8563] Slim::Player::Source::streamingSongIndex (1486) Clearing out song queue first
[08-06-15 09:34:39.8567] Slim::Player::Source::streamingSongIndex (1503) Song queue is now 9
[08-06-15 09:34:39.8573] Slim::Player::Source::playmode (309) 00:04:20:10:01:57: Switching to mode play from stop
[08-06-15 09:34:39.8579] Slim::Player::Source::resetSong (1727) Resetting song buffer.
[08-06-15 09:34:39.8641] Slim::Player::Source::openSong (1828) Trying to open: file:///data/common/All%20Music/Wolfgang%20Amadaus%20Mozart%20-%20Symphonies%2038%20-%2041/10%20-%20Symphony%20No%2040%20in%20G%20minor%20K%20550%20-%20III%20Menuetto%20Allegretto.flac
[08-06-15 09:34:39.8651] Slim::Player::Source::openSong (2029) duration: [243] size: [74053179] endian [] offset: [0] for file:///data/common/All%20Music/Wolfgang%20Amadaus%20Mozart%20-%20Symphonies%2038%20-%2041/10%20-%20Symphony%20No%2040%20in%20G%20minor%20K%20550%20-%20III%20Menuetto%20Allegretto.flac
[08-06-15 09:34:39.8684] Slim::Player::TranscodingHelper::getConvertCommand (208) undermax = 1, type = flc, transporter = 00:04:20:10:01:57
[08-06-15 09:34:39.8688] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-wma-transporter-00:04:20:10:01:57
[08-06-15 09:34:39.8691] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-wma-*-00:04:20:10:01:57
[08-06-15 09:34:39.8694] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-wma-transporter-*
[08-06-15 09:34:39.8697] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-wma-squeezebox2-*
[08-06-15 09:34:39.8701] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-wma-*-*
[08-06-15 09:34:39.8704] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-ogg-transporter-00:04:20:10:01:57
[08-06-15 09:34:39.8707] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-ogg-*-00:04:20:10:01:57
[08-06-15 09:34:39.8710] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-ogg-transporter-*
[08-06-15 09:34:39.8713] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-ogg-squeezebox2-*
[08-06-15 09:34:39.8716] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-ogg-*-*
[08-06-15 09:34:39.8719] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-flc-transporter-00:04:20:10:01:57
[08-06-15 09:34:39.8722] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-flc-*-00:04:20:10:01:57
[08-06-15 09:34:39.8730] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-flc-transporter-*
[08-06-15 09:34:39.8744] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-flc-squeezebox2-*
[08-06-15 09:34:39.8755] Slim::Player::TranscodingHelper::checkBin (145) Checking formats for: flc-flc-*-*
[08-06-15 09:34:39.8758] Slim::Player::TranscodingHelper::enabledFormat (112) Checking to see if flc-flc-*-* is enabled
[08-06-15 09:34:39.8761] Slim::Player::TranscodingHelper::checkBin (153)    enabled
[08-06-15 09:34:39.8764] Slim::Player::TranscodingHelper::checkBin (155)   Found command: -
[08-06-15 09:34:39.8768] Slim::Player::TranscodingHelper::getConvertCommand (309) Matched Format: flc Type: flc Command: -
[08-06-15 09:34:39.8772] Slim::Player::Source::openSong (2058) This is an flc file: file:///data/common/All%20Music/Wolfgang%20Amadaus%20Mozart%20-%20Symphonies%2038%20-%2041/10%20-%20Symphony%20No%2040%20in%20G%20minor%20K%20550%20-%20III%20Menuetto%20Allegretto.flac
[08-06-15 09:34:39.8775] Slim::Player::Source::openSong (2059)   file type: flc format: flc inrate: 2437 maxRate: 0
[08-06-15 09:34:39.8778] Slim::Player::Source::openSong (2060)   command: -
[08-06-15 09:34:39.8782] Slim::Player::Source::openSong (2079) Streaming with format: flc
[08-06-15 09:34:39.8786] Slim::Player::Source::openSong (2093) Opening file /data/common/All Music/Wolfgang Amadaus Mozart - Symphonies 38 - 41/10 - Symphony No 40 in G minor K 550 - III Menuetto Allegretto.flac
[08-06-15 09:34:40.0103] Slim::Player::Source::playmode (412) 00:04:20:10:01:57 New play mode: play
[08-06-15 09:34:40.0223] Slim::Player::Transporter::play (104) Setting DigitalInput to 0 for [file:///data/common/All%20Music/Wolfgang%20Amadaus%20Mozart%20-%20Symphonies%2038%20-%2041/10%20-%20Symphony%20No%2040%20in%20G%20minor%20K%20550%20-%20III%20Menuetto%20Allegretto.flac]
[08-06-15 09:34:40.0227] Slim::Player::Transporter::setDigitalInput (184) Switching to digital input 0
[08-06-15 09:34:40.0258] Slim::Player::Source::playmode (581) 00:04:20:10:01:57: Current playmode: play
[08-06-15 09:34:41.0342] Slim::Player::Source::trackStartEvent (1593) Got a track starting event
[08-06-15 09:34:41.0347] Slim::Player::Source::trackStartEvent (1609) Song 9 has now started playing
[08-06-15 09:34:41.0360] Slim::Player::Source::trackStartEvent (1637) Song queue is now 9

Seek to the "middle" of the track using the Webinterface

[08-06-15 09:35:21.7848] Slim::Utils::Misc::msg (1349) Warning: [09:35:21.7843] Use of uninitialized value in concatenation (.) or string at /opt/SqueezeCenter_svn/7.1/trunk/server/Slim/Player/Source.pm line 1067.
[08-06-15 09:35:21.7852] Slim::Player::Source::gototime (1067) trying to gototime 127.489436619718 (rangecheck: )
[08-06-15 09:35:21.7858] Slim::Formats::FLAC::_seekNextFrame (1072) Reading 18448 bytes at: 38851843 (to scan direction: 1)
[08-06-15 09:35:21.8038] Slim::Formats::FLAC::_seekNextFrame (1096) Scanning: len = 18448, start = 0, end = 18432
[08-06-15 09:35:21.8328] Slim::Formats::FLAC::_seekNextFrame (1117) Couldn't find any frame header
[08-06-15 09:35:21.8335] Slim::Player::Source::_time2offset (137) 127.489436619718 to 0 (align: 1 size: 74053179 duration: 243)
[08-06-15 09:35:21.8340] Slim::Player::Source::gototime (1139) Going to time 127.489436619718, offset 0
[08-06-15 09:35:21.8348] Slim::Player::Source::gototime (1196) Stopping playback for 00:04:20:10:01:57
[08-06-15 09:35:21.8369] Slim::Player::Source::gototime (1235) Restarting playback for 00:04:20:10:01:57
[08-06-15 09:35:21.8396] Slim::Player::Transporter::play (104) Setting DigitalInput to 0 for [Slim::Schema::Track=HASH(0x56c0df0)]
[08-06-15 09:35:21.8403] Slim::Player::Transporter::setDigitalInput (184) Switching to digital input 0
[08-06-15 09:35:22.7437] Slim::Player::Source::trackStartEvent (1593) Got a track starting event
[08-06-15 09:35:22.7440] Slim::Player::Source::trackStartEvent (1609) Song 9 has now started playing
[08-06-15 09:35:22.7452] Slim::Player::Source::trackStartEvent (1637) Song queue is now 9

Seek to the "end" of the track using the Webinterface

[08-06-15 09:35:50.8779] Slim::Utils::Misc::msg (1349) Warning: [09:35:50.8774] Use of uninitialized value in concatenation (.) or string at /opt/SqueezeCenter_svn/7.1/trunk/server/Slim/Player/Source.pm line 1067.
[08-06-15 09:35:50.8790] Slim::Player::Source::gototime (1067) trying to gototime 198.507042253521 (rangecheck: )
[08-06-15 09:35:50.8797] Slim::Formats::FLAC::_seekNextFrame (1072) Reading 18448 bytes at: 60494146 (to scan direction: 1)
[08-06-15 09:35:50.9156] Slim::Formats::FLAC::_seekNextFrame (1096) Scanning: len = 18448, start = 0, end = 18432
[08-06-15 09:35:50.9418] Slim::Formats::FLAC::_seekNextFrame (1117) Couldn't find any frame header
[08-06-15 09:35:50.9421] Slim::Player::Source::_time2offset (137) 198.507042253521 to 0 (align: 1 size: 74053179 duration: 243)
[08-06-15 09:35:50.9425] Slim::Player::Source::gototime (1139) Going to time 198.507042253521, offset 0
[08-06-15 09:35:50.9432] Slim::Player::Source::gototime (1196) Stopping playback for 00:04:20:10:01:57
[08-06-15 09:35:50.9459] Slim::Player::Source::gototime (1235) Restarting playback for 00:04:20:10:01:57
[08-06-15 09:35:50.9480] Slim::Player::Transporter::play (104) Setting DigitalInput to 0 for [Slim::Schema::Track=HASH(0x56c0df0)]
[08-06-15 09:35:50.9484] Slim::Player::Transporter::setDigitalInput (184) Switching to digital input 0
[08-06-15 09:35:51.8960] Slim::Player::Source::trackStartEvent (1593) Got a track starting event
[08-06-15 09:35:51.8963] Slim::Player::Source::trackStartEvent (1609) Song 9 has now started playing
[08-06-15 09:35:51.8975] Slim::Player::Source::trackStartEvent (1637) Song queue is now 9