Instrument patches off by one when loading from an xml file

When I load an xml file with midi instrument patches in it they are interpreted as the wrong instrument. It always sets the instrument in the mixer off by -1. ex: If the patch calls for bari sax which is patch 67, it loads as tenor sax which is 66. The problem appears to be that almost all sound fonts are zero based rather then one based.. The instruments patches are 0 - 127 for general midi rather that 1- 128.
I am using MuseScore Version 0.9.5 on Windows xp sp3. THe sound font currently in use is the Chaos 8M sound font.
Attached is an xml file I have tried. It was created by lasconic's nwc2musicxml converter. There are other problems in the xml file that I am aware of and will address the with lasconic in a private email. The instrument patch information is however correct. It is calling for patch 67, Baritone Sax.

Regards
Keiti