Weird, not heard of that one. What OS, and if Leopard, are you using Spaces?
Diagnostic tricks to help locate the cause of the problem:
1) quit Word, then hold down shift while launching Word. If the problem
disappears, it was probably due to a corrupt Normal template.
2) Log out of your user account, then hold down shift while logging back
in. If the problem disappears, it is probably due to some conflict with
the login items/utilities in your user account.
3) create a new user account in OS X and test in that one. If the
problem disappears, then the installation is fine but some user-specific
file has corrupted.
