I'm not entirely sure what your problem is Pe@rson. Sounds like you don't have any key assignments for some reason or other.
Try going to: Start/All Programs/Microsoft Games/FS2004/TroubleShooting/Reset Defaults
You will lose any settings you have, so be sure to make a note of them. I'm not sure if that will work, but it is worth a try.
Let us know if you have any luck!
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