Symantec service Framework has stopped working

Hi.

 

Upgraded to Norton Anti Virus 2011 yesterday and when I click on the performance tab, once the GUI switches round it sits there for an age before a window with 'Symantec service Framework has stopped working' pops up.  I have to close the program but when I do that the GUI disappears.

 

I can't bring the GUI back up without a reboot.  It wont run scans while the GUI is gone from Programs > Norton > Run Quick Scan. 

 

2 instances of ccSVCHst.exe are still running in Process Explorer when the GUI is gone but I can't scan anything.

Had no such issues with NAV 2010.

 

I'm using Windows 7 Home Premium with all the latest updates.

 

Thanks