I have version 2.9.143 of SiteAdvisor - you probably have 2.8. See here for the background:
http://community.mcafee.com/showthread.php?t=222622 This worked today for me on 2.9.143. I suspect it will work on prior versions as well,
but the name of the service and process in prior versions may be different, so you'll need to track that down for your version.
Periodically, I've had an issue in the past with prior versions where SiteAdvisor will stop functioning. The SiteAdvisor icon will be greyed-out and Google searches aren't rated. The fix in the past has been to uninstall, and then reinstall SiteAdvisor. Annoying since it would happen frequently.
See, for example:
http://community.mcafee.com/showthread.php?t=214552&highlight=%22communication+problems%22 Today, my SiteAdvisor IE Toolbar icon greyed out on all sites. There was no "We're experiencing communication problem right now" notification.
The strange thing (new behavior), is that it did still function in Google searches. Results were color coded.
Rather than uninstalling and reinstalling, I tried this (on XP Pro, SP2, running IE6):
-Close IE.
-Click Start\Run.
-Type services.msc (opens the Services interface).
-Click OK.
-I attempted to stop the McAfee SiteAdvisor Service. It would not stop, but went in to an indefinite Stopping status.
-Opened Task Manager.
-Ended Process on McSACore.exe (the process the service above runs). That stopped the service.
-Started the McAfee SiteAdvisor Service (which re-started the process McSACore.exe).
Opened IE, and the icon was functioning again.
A reboot of the computer should have the same result, but I didn't want to wait for that.
Might be worth a try the next time you have a greyed-out icon.
Pat