Thanks - That's an interesting theory- I'll check out the BIOS settings on the function key. BTW, deinstalling the Citrix client didn't help with this function key issue. It's too bad, as I thought that was what was causing this silliness. Typing with this notebook is an exercise in avoiding the fn key so as not to bluescreen! The other possibility is that I installed a driver for a CD rom burner on the notebook that Windows XP didn't like. Unfortunately, I can't deinstall this driver.
Worst comes to worst, IBM ThinkPads now have a hidden partition that contains a factory image. I'll backup my data, hold the f11 key when booting, and reimage, the PC, and then restore the data and software (except, maybe, for the CD ROM burner driver!).
Thanks again