After entering my commercial key, Toad accepts it but when the application is restarted, license shows as trial and the commercial key is no longer registered.
WORKAROUND :
1) Exit out of Toad
2) Go to C:\Documents and Settings\\Application Data\Quest Software\Toad for Oracle\User Files
3) Check for a QSAuth11.key file. If found remove it and start Toad, register the commercial key and test the issue.