Heeeey... wait a minute! An older script is getting me the same "TclNotifier". And I have a compiled version of it that doesn't.

I'll check the installation. Although I haven't installed any modules recently, as far as I can remember. Maybe it's the Windows Update thing.

(EDIT) Please accept my apologies. Something in this multi-desktop program I've been using seems not to be fully compatible with Tk (or the other way around?). I'll get rid of this thing.
Thanks for all who answered - I hope it was not a waste of time for you. At least somebody else in the same trouble may read this and find a solution.