And this is why I use Mp3's.
In the simplest terms I can think of, Sometimes PRGM2k3 doesn't reset your MIDI drivers. This means that if a song drops your volume, then all songs will have that dropped volume. It causes problems with poorly made MIDI (most good ones have a MIDI reset in the front of it.) If you want, you can send me the MIDI or even better, what you have on your project and I can get those MIDIs to have a Midi reset. If that don't work we can assume your computer hates MIDI