>>"It just happened that I'd load a song and then completely new performances or patches would appear."
Okay, gotcha: In that case, the song has been saved as an .svq file with the Song + Sound option, which saves not only the sequenced song, but also all the performance settings including the patches, at the beginning of the song. It takes up a bunch of measures at the beginning of the song, which is why it takes a while for the song to actually start once you press Play: It's loading the sysex. All the songs on the demo disk are saved this way.