My dev system has very few tracks. Some genres contain only a single track. If I ask for a random mix of tracks from a genre that only has one available track, SC7 logs errors like this:

[08-12-03 19:41:24.6651] Slim::Control::Request::notify (2073) Error: Failed notify: Carp::Clan::__ANON__(): Error executing 'SELECT me.id, me.url, me.content_type, me.title, me.titlesort, me.titlesearch, me.album, me.tracknum, me.timestamp, me.filesize, me.disc, me.remote, me.audio, me.audio_size, me.audio_offset, me.year, me.secs, me.cover, me.vbr_scale, me.bitrate, me.samplerate, me.samplesize, me.channels, me.block_alignment, me.endian, me.bpm, me.tagversion, me.drm, me.musicmagic_mixable, me.musicbrainz_id, me.lossless, me.lyrics, me.replay_gain, me.replay_peak, me.extid FROM tracks me WHERE ( id IN (  ) ) ORDER BY RAND()': DBD::mysql::st execute failed: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ) ORDER BY RAND()' at line 1 at /path/to/server/CPAN/DBIx/Class/Storage/DBI.pm line 771.

[08-12-03 19:41:24.7252] Slim::Schema::Storage::throw_exception (70) Error: Error executing 'SELECT me.id, me.url, me.content_type, me.title, me.titlesort, me.titlesearch, me.album, me.tracknum, me.timestamp, me.filesize, me.disc, me.remote, me.audio, me.audio_size, me.audio_offset, me.year, me.secs, me.cover, me.vbr_scale, me.bitrate, me.samplerate, me.samplesize, me.channels, me.block_alignment, me.endian, me.bpm, me.tagversion, me.drm, me.musicmagic_mixable, me.musicbrainz_id, me.lossless, me.lyrics, me.replay_gain, me.replay_peak, me.extid FROM tracks me WHERE ( id IN (  ) ) ORDER BY RAND()': DBD::mysql::st execute failed: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ) ORDER BY RAND()' at line 1 at /path/to/server/CPAN/DBIx/Class/Storage/DBI.pm line 771.

I'm using CLI commands like the following to request the mix:

randomplaygenreselectall 0
randomplaychoosegenre Podcast 1
randomplay tracks

Sometimes SC7 will actually play the single track, but other times it will not.

SVN info:

Path: server
URL: https://svn.slimdevices.com/repos/slim/7.3/trunk/server
Repository Root: https://svn.slimdevices.com/repos/slim
Repository UUID: 60ad55ce-86ed-0310-8cf8-f9d879be5ea1
Revision: 24188
Node Kind: directory
Schedule: normal
Last Changed Author: andy
Last Changed Rev: 24188
Last Changed Date: 2008-12-03 12:07:25 -0500 (Wed, 03 Dec 2008

This is on Ubunto 8.04 LTS, apparently running MySQL 4.1.15.