This is an age old problem that I've had since I first started working on the OpenMOD library some few years ago.

What are all the compression formats used on the samples used in a Impulse Tracker module?

I will post the exact issues I had with loading and playing back samples from the library. (still in development, but halted due to time constraints and other projects) I have to look it up in the source. And since I'm in the process of converting all my sources to FPC/Lazarus, I don't have a running demo app. to test things out yet.

One thing I do remember quite specifically though was that when I took a mod that was created (seemingly) with Impulse Tracker it's self and then tried to load one saved (modified or created by) ModPlug Tracker it would cease to load properly.