Do the MIDI files (T0000001.MID etc) play back ok using other MIDI software?

On Windows, all the MIDI files are valid play ok through Media Player, Cakewalk etc but there may be something in the WINE setup which makes the program write invalid files?

For example, the MIDI specification uses 7-bit "bytes" instead of 8, for numbers, and maybe the conversion isn't working properly when the file is writen?