Sorry, no ideas other than that. But that's generally a good fix. Even if it installed properly, sometimes it takes a reboot if your computer's been on for awhile.
Oh, you could also try doing a complete uninstall (through My Computer, System Tasks, Add/Remove a program), rebooting, and then reinstalling. If there were problems when you initially downloaded/installed it, you might be having residual effects.
Attention: NOTHING on this site may be reproduced in any fashion whatsoever without explicit consent (in writing) of the owner of said material, unless otherwise stated on the page where the content originated. Search engines are free to index and cache our content. Users who post their account names or personal information in their questions have no expectation of privacy beyond that point for anything they disclose. Questions are otherwise considered anonymous to the general public.