I suggest you completely remove and then reinstall your software following the method laid out here: http://service.mcafee.com/FAQDocument.aspx?lc=1033&id=TS101331
It sounds like it has become corrupted in the upgrade process.
Edit: If you have an extra program called Security Scan Plus registered in your program list please uninstall it., It's merely a sales tool and is not needed.
Absolutely brilliant. Many thanks for the prompt response. I have used McAfee for many years without a problem so panicked.
Glad to help.