Mail 4.2 Breaks (Disables) OF Plugin
 

I just ran the Snow Leopard 10.6.2 update and it disabled the Clip-o-Tron 3000 plugin for OmniFocus. Really Annoying. I know it's not OG's fault, just wish Apple would give you guys a heads up. Though I should start a thread. If anybody has a fix, please post!

They did give a heads-up, they broke it with the last release :-)

Now all you have to do is go back to the Mail preferences and reinstall the plug-in (and possibly restart Mail, I don't recall). OF knows how to put a new signature in place so that Mail won't reject the plug-in until the next time Mail changes.