Laptop Fn+Fx key combos borked

So, I have a laptop.  Like most laptops, it has the Fn key, which, when used in conjunction with the F1-F12 keys, can do special things.  In my case, it can do volume up and down, mute, screen brightness up and down, etc.

When I turned the computer off last night, everything worked fine.
when I turned it on this morning, the key combo for volume up, volume down, and mute are all broken.  They open things like notepad, and calculator.  The screen brightness ones still work, just the volume ones are borked.

Just now, while typing, I tried them again, and this time instead of calculator or notepad, they made "m" and "f" in the typing area.  What?

In the meantime, I can use the toolbar icon to control volume, but, you know, it's a little annoying when I have hotkeys that should work but don't, for no good reason.

If it matters, I'm using WinXP SP2.

Any ideas on what's gone wrong, and how to fix it /comp/?  Thanks for your time!

is it a dell, sony or hp laptop?

Check your laptop manufacturer's website for a download for the hotkeys utility. Uninstall the old one, reinstall the downloaded one. You might have had a file go corrupted in the old utility that has stopped it working.

It's none of the above.
It's an XtremeView laptop built by some obscure company called TTX
www.ttx.ca
For the past year it ran perfectly fine with no problems whatsoever until now.
That's a great suggestion. I will definitely go and see if I can find the hotkey utility.
But assuming I do, where is the hotkey configuration saved usually? I mean, it's not exactly a program I installed separately...or so I'd think?

I guess it would be a program that was already pre-installed on the laptop when you got it. Check your Add/Remove Programs list, plus obvious places in the Start menu (Start>Programs>TTX perhaps) or on the hard drive (C:/Program Files/TTX). The reason why your hotkeys no longer work but the brightness keys do is because the hotkeys call Windows programs and need to be governed by a utility running in the background, whereas the brightness controls just talk directly to the hardware (the backlight inverter). Anyway, as I suggested, check the website, or failing that check the CDs that came with your laptop for a utility disc or something, and reinstall it from that.

Turns out it was some sort of weird audio utility causing the problem.  I reinstalled it, and everything worked again.  Weird stuff.  Thanks for your help!