Upgrade problem with FCP X

Hi,

I purchased FCP through the App store, when it was first released. Since then it has not upgraded.

I noticed that there were at least two upgrades released.

In the App store under my list of purchased products, it is there. When I hit install I get an error message: We could not complete your Purchase. Final Cut ist already installed on this computer. Choose Software Update from the Apple menu to check for available updates.

Unter the Update tab there is no available update, and under the suggested Software Update I am also told, everything is up to date.

Back in the App store, when I click buy in the FCP Window, I get this message: Final Cut Pro 10.0 is already installed and was not purchased from the Mac App Store. Do you want to buy Final Cut Pro 10.0.3?

Like I said, I did purchase FCP through the App store, and it also shows up under the purchased tab.

Please, could someone help me, what I can do to get FCP to update?