[whpalmer4]

You may be low on memory. I've discovered that after some use of both OmniFocus and other apps I'll eventually get to a state where tapping on actions in the outline doesn't do anything (and if I hook up the iPad console via the iPhone Configuration Utility, all sorts of messages about very low memory are emitted). One thing that sometimes works is going to a different perspective and then back. If that doesn't work, reboot the iPad.

This problem is likely made worse by 4.2 and multi-tasking—I wish Apple had put 512MB of RAM in the iPad like they did in the iPhone 4.