http://bugs.winehq.org/show_bug.cgi?id=20867
--- Comment #21 from Jussi Saarinen jussaar@mbnet.fi 2012-03-14 20:57:10 CDT --- (In reply to comment #20)
With wine version 1.4 I have noticed something interesting. When I choose to save mus-files using simply "Save" instead of "Save As", the files seem to work OK. Only when saving files using "Save As" they don't work. I am not sure yet whether the functionality has improved since last tested or did I simply notice this just now.
I have now confirmed that the behavior is similar also in wine version 1.3.2. So looks like no recent modifications have changed the program's behavior.