Aperture 3 stuck in trial mode - won't remember license key or authorize

I can't get Aperture 3 to stop asking me for my license key. In About Aperture, it says "Trial", but also shows it as licensed to me with my licnse key.

I have tried ALL the recommended solutions I can find that seem to work for others on this forum BUT nothing works. This is pretty stupid.

Platform is 13" MBPr with OS X 10.8.3. All installation and authorization attempted with admin account. Deleteing all Aperture files in between attempts. Repaired permissions also.

Approaches:

1) Installed 3.0 from original purchased full-version disc (authorized during install). Asked for trial or authorization. Repeatedly asked for authorization with a good license (no license error). Nada.

2) Tried the above + deleting the ProApps/ProAppsSystemID + reauthorizing. Nada.

3) Installed 3.0 from original disc (authorized during install) + upgraded to 3.4.3 before authorization. Try to authorize. Nada.

4) Installed 3.0 from original disc (authorized during install) + run once or twice to authorize (which doesn't work) + upgraded to 3.4.3. Try to authorize. Nada.

5) #3 and #4 + #2. Nada.

Reinstalling the system software is not an option (and is a cop-out solution, IMHO).

Any help to be had here?

Is there any way to convert to the App Store version without repurchasing? I suspect a clean install from the App Store would probably work.