My File > Open Recent never shows any files.
 

Is there a setting for this? What doesn't OG display recently opened files.

Screencapture:
[url]http://d.pr/7WDq[/url]

I have the exact same issue. Very frustrating.

Mac OS X 10.6.8
Omnigraffle Pro 5.3.6

Works for me with 10.6.8 and 5.3.6.

Maybe try removing
[code]
~/Library/Preferences/com.omnigroup.OmniGrafflePro.LSSharedFileList.plist
[/code]
(In the Finder, cmd-shift-G + "~/Library/Preferences" to get to the folder)

Is the Open Recent menu empty only for Omnigraffle? If not, check the Appearance panel in System Preferences. Make sure that "Number of recent items" isn't set to "None" for Documents.

While that's a global setting, choosing "None" there does result in the OP's Omngraffle screenshot.

Bingo! Thanks for the solution, John! My "Number of recent items" for documents was set to "None."

Removing the preferences file didn't work, but setting the "Number of recent items" for documents to something other than "None" in "System Preferences > Appearance" worked. Thank you!