(GBS) playback issue when time is greater then about 6:40:00

[Sonic-The-Hedgehog-LNK1123]

I don't know if it's foo_gep or this library that is causing it, but if a track's time it set to above 6:43:00 the track no longer plays.
Memory usage seems normal.
Integer overflow or something?

Edit: @kode54 I'm 100% sure there's a 32 bit integer overflow somewhere in either this or foo_gep.

This bug is preventing me from creating a proper 10 hour extension of a Game Boy music track.