Problem with Fn key on my laptop

[JeffPetersen]

I've run into a strange problem with Linux Mint 12. I've been happily running it for several months now, but when I was using my laptop on the weekend I noticed something strange.

My laptop has a key marked Fn (separate from the function keys at the top of the keyboard). When I press Fn and certain keys, a different character appears -- for example, pressing Fn + M results in a zero being typed.

That's the normal behaviour. Now, it seems that behavior of the keys that work with the Fn key has been reversed -- I press M and get a zero; press Fn + M and I get a M. This only started happening the other day, and only happens with my user account. I logged in under the laptop's guest account and all the keys work as they should.

I've been searching for solutions to this problem, as well as changing various settings, but nothing. Has anyone else run into this problem? If so, what was your solution (aside from doing a full reinstall of Mint)?

Thanks in advance!

Jeff