[MacBerry]

Assuming OF on the desktop is up to date, I'd re-name Omnifocus.ofocus on MobileMe to Omnifocus.old, then re sync the desktop, telling it to use the local copy of the file if asked.

Then, in OF on the iPhone, go to settings and tell it to reset the database. Make sure your sync settings are correct, then sync and tell it to use the server copy if asked.

Backup first of course.

HTH

Mark