I'm stuck on compressor 3.5 and I want to update to 3.5.3 because I'm having some issues with "this computer" not available to submit to. It's a fresh install - snow leopard, and it was working a couple days ago, just seems to have stopped working.
I ran system update, but it's saying there is no update. FCP is 7.0 and compressor is 3.5
What exactly do you get when you run "Software Update"?
Probably there is a System Update, QT Update, ProApps Kit or whatever that you will need to install before being able to update FC?Motion.
Then you should get a "ProApps Update" downloadable.