Keyboard resets after "Sleep"

Sorry if this is the wrong forum, but in Vista, my Canadian English (US
layout) keyboard keeps resetting after Sleep mode. My ? changes to an unusual
E, my ' becomes `, that kind of thing. All of the alphabetical letters are
fine, it's the punctuation that seems to switch to an extended keyboard. I
have to reboot my PC or browse through Control Panel -> Keyboard (changing
nothing, just opening and closing the program) to reset it.

Any ideas on how to prevent this from happening? I am using a Dell PC and
keyboard, with Vista Basic.