Moved to its own thread in General Discussion for better attention. The particular SiteAdvisor issues you posted to have been solved.
Assuming these conditions persist and you are talking about home products as against Enterprise,, what operating system and service pack are you using and what version of Internet Explorer is installed regardless of whether or not it's your default browser?
What McAfee software do you have installed and what version? How much free memory (RAM) and free hard drive space do you have?
Have you tried free Technical Support - online chat or by phone?
Did you try running the McAfee Virtual Technician to see if it will fix anything?