I've uploaded a plethora of music .mp3's and a handful of station ID mp3.s .They all play back here in the studio on our Station Playlist on-air automation, but on AutoDJ the Station ID's cause playback to suddenly stop, while the music .mp3s. play ok. What difference in the files should I be looking for to analyze this? Has anyone seen this before? I've tried the station ID's in their own interval playlist, and also mixed into a standard playlist, same behavior either way.

What are you using for the auto DJ ?  We ran into a situation where ices.cc (the software used for auto dj in some cases) will
not play files shorter than 10 seconds and the stations ID's were shorter than 10 seconds.   Liquid Soap will work, however
there have been some problems with Liquid Soap recently as well where after updating in Centova it breaks Liquid Soap
and causes some files to mysteriously make Liquid Soap stop and not automatically restart.   Also we found that the file names
themselves can cause problems in Liquid Soap, something you may want to research.  Your audio may be fine but the file names
might have weird symbols etc that can actually gum things up.  Hope that helps.

You should also check if your files are encoded with constant or variable bitrates. If they are VBR then re-encode them to CBR. VBR files are known to cause some issues and not always being correctly handled by AutoDJ software.