Why are MS Flight Simulator X keyboard commands suddenly not working on Macbook Pro with Windows XP?

In using MS Flight Simulator X on my Macbook Pro (it has Windows XP installed via Boot Camp), many keyboard commands which used to work as intended no longer do so. For all I know, most or even all of the keyboard commands no longer work. They either produce no response, or they produce either another unrelated response or an error message.

I use this application infrequently, but I can't think of anything that has changed.

The one bit of insight I can offer is that for one particular command, I went to FltSim X's settings and reassigned the particular keystroke to exactly what it already was and then it worked as it was supposed to work. This seems to suggest that I will have to reassign all keystroke commands to what they have already been - - a HUGE task.

Has anyone else seen this behavior, and is there a simple fix for it? Thanks for any insights.

(PS: I have uninstalled and reinstalled MS Flight Simulator X and the problem remains.)