Why does Internet Explorer 8 freeze my desktop? (Windows 7 64-bit with Norton IS 2011)

If I leave IE open it freezes my desktop until I close the processes it creates with task manager. After an hour there can be as many as 20-25 running processes from one open IE window. I posted in an Internet Explorer help forum and it was suggested it might be a "hijackware infection" and I should post here.

 

Full details of the issue and steps tried to resolve it can be found in my posts here:

http://social.answers.microsoft.com/Forums/en-US/InternetExplorer/thread/0e6b678c-7f67-4773-b0a2-4d07d92631bc/?prof=required

 

If anyone has any suggestions on what the issue could be, that would be great, thanks!