I’m using the same with no issues even vaguely similar, I’ve had mostly successes with it, when it hasn’t worked it hasn’t displayed anything like you are experiencing, although I have seen it as an issue on other forums. I haven’t seen any explanation other than a possible problem with Lion, which you aren’t using.
The only other suggestions I could offer is to try logging in as a different user, or re-install.
Not much help I’m afraid
“My Name is Steve and I’m an FCPX user”