I ran into this bug testing my GrabPlaylist plugin on the 6.5b1 (build from Sept 10, seems to actually be newer than the 6.5b2 RPM released today).

I ran a playlist on one of Squeezebox 2's, and went to my Squeezebox 1, and used GrabPlaylist to bring the playlist over.  Part of what GrabPlaylist attempts to do is use Slim::Player::Source::gototime() to advance the song to the point where it was before.  At the point I did this, the song was about 1/2 way complete on the source player.  Seemed to work fine.

When I hit rewind to go back to the start of the song, the progress bar seemed to reset to the point where it was when I did the first gototime() call (something like 1:37 into the song).  The song played all the way through, but the status bar ran until it showed 100% complete, and just stayed there.  Then, when the next song came up, it immediately showed as being 1:37 into the song.  The song played correctly from the start of the song all the way through, but the status bar seemed to start counting at 1:37.

The same behavior occurred when I used the plugin to transfer the playlist back to the Squeezebox 2 from the Squeezebox 1, now occurring at whatever point the SB1 was at.  As such, it would seem to be a server issue, rather than a player issue.

The core functionality of GrabPlaylist is this:

    Slim::Control::Command::execute($dest, ['stop']);

    my $offset = Slim::Player::Source::songTime($source);

    Slim::Player::Playlist::copyPlaylist($dest, $source);
    Slim::Control::Command::execute($source, ['stop']);
    Slim::Control::Command::execute($dest, ['play']);
    Slim::Player::Source::gototime($dest, $offset, 1);