Bpm for Mod Tracker Files

Hi,

I've been experimenting with Mod Tracker files (s3m, mod, it, xm) which can be used as audio clips, this is great; but there seems to be a big problem. I've done some measurements with .xm and .it files and found they were out of time with a wav file that I had generated from them. On further research I have found that it is the format of those files that is the problem, they are made to faithfully reproduce the floating point errors that occurred on the Amiga where they seem to have been invented.

Does anyone know about these? and does anyone know whether you can get bpm accurate results out of them?

Cheers,
Alistair