Itunes stops responding after approximately 20 seconds after launching the program.

This issue apprear to only have started in the last couple of days. I have re-installed Itunes 11 with no success. The resolution suggested on the Itunes troubleshooting page has been helpful somewhat in that iTunes works well in safe mode, however I have confirmed that there are no 3rd party plug-ins installed in the folder as suggested. What else may be the cause of this issue?