Shortly after a restart, the arrow and navigation (Home, End...) keys on my numeric keypad will randomly stop working, and -- regardless of the state of the NumLock -- return only numbers. I notice this the most in browser applications (like this edit box) but the same effect is true on the command line and in desktop applications like Word.

I swapped keyboards and now use a Microsoft keyboard (both are USB keyboards) but the same behavior persists. I also tried a clean boot to clean out startup programs but this made no difference. The separate arrow keys and navigation keys between the QWERTY keys and the numeric keypad work fine, but my strong preference (dating back to DOS and MS Flight Simulator) is to use the navigation keys in the numeric keypad.