Exporting the tune in compatibility mode doesn't do much justice either. Neither did converting it to screamtracker and back to protracker.

Can't check at the moment but I am 99% sure that it happens because of the separator pattern you have used in this MOD. You cannot use separator patterns in MOD files, but OpenMPT doesn't prevent you from doing so for some reason. The problem is that other applications rightfully interpret the separator as a pattern number, and try to load this pattern in the sample data area, so there's nothing left to load for the sample loader.

Confirming suspicion.

Ok, starting from revision 860, separator patterns are not allowed in MOD files anymore.

Please check if http://sagagames.de/stuff/mptrack.exe fixes the problem for you.

I am confirming the fix, however, there's another slight problem.
If resaving mod with separator pattern in the new revision, all patterns after separator get lost. Patterns above max number get nuked.

I'll add a warning on save in the next version... (or just change the save mechanism in another way)

Ok, please check if the MOD saving behaviour is better now (same URL).

Confirmed.