I believe I have mentioned info about my system if not in this CTD thread, then in the FS9 one (that used to be the FSX one). Anyway, it has nothing to do with your system. It's a bug in the gauge. I haven't heard one person who uses the FMC fully report not having the issue.

Luckily, I think CS is close to (in the next three months or so) releasing a new patch that will fix it.