Is it possible you have akeyboard with dual purpose F keys? The one I'm o right now has a whole bunch of extra actions on the F keys - Help, Undo, Redp, etc, etc. Their function is controlled by an extra 'F Lock' key. It's bloody annoying but it's a Microsoft keyboard and I much prefer them as they fit my hands well, are comfortable, and are good quality so I just put up with the oddities.