Anyone has anything like that?
When I hit F10 (or even F9) I got an invisible entity which tricks Expose to believe there is a valid window there (though a check at 'Window' menu item of OmniFocus yields nothing)
I stumbled at this entity by accident (it only exists in Expose's imagination ;)), when I was moving a cursor. As usual it highlights legit window with just a blue glowing frame, but this entity is lit blue completely.
It's not a deal breaker, though it's annoying.
07'MBP / 10.6.2 / up to date.
P.S. OF runs maximized, just tried it with less estate - same results.