can't get pmsounds to work with custom offsets via fsconv

I'm having a problem with pmsounds. It works for the standard gpws callouts etc and I've even added some custom sounds like when the speedbrakes are deployed (spdbrk,0bd4,4,16384,cyc,50) which also works.What I'm trying now however is to play sounds for some non-standard offsets that I've added via fsconv (for Level-d 767 FSX).For example, at offset 8ba3 is the APU starter knob. The position of the knob sets offset 8ba3 to 0, 1 or 2.I know that this part works because I've written a small program that polls this offset and I can see thatthis offset holds the correct value according to the knob's position.I'm however not able to get pmsounds to work. I'm simply trying to get it to play a sound when this knob is turned (as an example).This value is 1 byte so I've tried things like "testfile,8ba3,1,1,on" and many other variants. Still, no sound is played.Any ideas? (Using Windows 7, latest version of everything and registered fsuipc)