I have been working on this as I've seen the same problems, I have got a workaround, but as I'm not a fully proficient
VB programmer its not the prettiest way to go and has limitations.
What I have found is that the process used by ibuscomm is sendkeys, this method which last I heard was completely broken on Vista doesn't appear to be picked up by Centrafuse even on XP. However, by modifying the code to use Sendinput, Centrafuse can pick up the commands.
The downside, is that due to my short amount of free time, I've been unable to re-code it much to take multiple keypresses, it will only take one keypress, so you'd have to change the hotkey settings (not too hard).
If anyone either wants the code, source, exe or even better can code it better to take multiple inputs, then please let me know!
P.S. I haven't yet tested this in my car, but by clicking the 'Simulate Keypress' button I can control Centrafuse... I'll install my car PC at some point!
Regards,