[TonyD]

Thanks itmiller. That helped! Your solution didn't give me a result but helped me solve it.

My steps:

I looked in System Preferences -> Keyboard -> Keyboard Shortcuts -> Services and saw OmniFocus:Send to Inbox was checked but no keyboard shortcut was listed.

I then went to OmniFocus preferences -> clippings, and entered a keyboard shortcut ending in C. OmniFocus dialogue box appeared complaining about System Preferences being open. I clicked Cancel option. My shortcut remained recorded in Clipping settings.

I checked System Preferences -> Keyboard -> Keyboard Shortcuts -> Services and saw OmniFocus:Send to Inbox had the appropriate shortcut.

I opened Textedit to test. Wrote some copy, highlighted some of it and did the keyboard shortcut: it didn't work!

So, I closed Omnifocus, then launched it again. closed Textedit and relaunched. Tried it again: it worked!

Now, I'm not totally convinced that the sequence above provided the solution. I suspect there's a bug and it's just a matter of trying again and again until something just gives.

Info for the Omnifocus people:

Mac OS X version 10.6.4
Omnifocus 1.7.5 (v77.41.6 r121031) in trial mode.

This has taken up 90 minutes :(

Not so productive....