I recently purchased a serial number from a person to upgrade a version of final cut that I legally own the serial number for. I believe that the new serial is a non-legal one. Now the version that I own, even after a reinstall won't allow me to move the windows around normally, it keeps giving me the stalling rainbow wheel making it imposssible to work. I have deleted the new version completely and reinstalled system software, as well as deleting some funky things in my carbon lib that were relating to an airport. What else can I try to do to restore its functionality without paying the exorbitant amount of money for applecare support?
Profuse Gratitude in advance for any help in this matter...

Profuse Gratitude in advance for any help in this matter...