Cannot completely uninstall Office Plugin

Cannot completely uninstall Office Plugin

I am trying to uninstall the Zoho plugin for MS Office. (WinXP, Office2003.) I've gone to the Add/Remove Programs menu, and everything appears to operate normally, but when I open MS Word, the Zoho menu entry is still there. It doesn't DO anything, but I can't get rid of it. I've tried a couple of registry cleaning tools like CCleaner and TweakNow, but the menu item remains. Any ideas?