[Brian]

We've looked into this still further and discovered that Safari 4 completely breaks OmniFocus' mail processing rule. It also partially breaks OmniFocus' ability to clip mail messages that use HTML to format their content.

For clipping, Safari 4 beta breaks the mail Clip-o-tron for HTML messages. However, if you select content in the message, you can clip that.

Previously, the only suggestion we had for folks encountering these problems was to revert to Safari 3 until Apple has a new build of Safari 4 ready with a fixed version of WebKit. That's still an option, of course.

If folks do want leave Safari 4 installed, our new suggestion is to temporarily disable the mail rule in OmniFocus' preferences, and to uninstall the clip-o-tron. This will prevent the error messages that folks have been getting in OmniFocus while still allowing them to use Safari 4 on their machines if they choose. (Though they will be unable to use the mail rule, and will have to manually select the contents of the messages they want to clip from mail.)

Editing thread title to reflect the most recent information. When Apple has a new build of Safari that fixes the WebKit bug causing these problems, we'll add a new post to this thread.