Thanks for responding, Alexander!
Yes, I do have a legitimate license for 5.1. I upgraded when Apple was offering a Studio upgrade for $199 if you sent them your old FCP discs. The update to 5.1.4 no longer shows up through Software Update, however. I called Apple, and the guy I talked to said they had pulled the update because they were wanting people to upgrade to Studio 2. He actually suggested I try looking on forums for someone who had a copy of the 5.1.4 update.
Thoughts?
Lonnie