Cannot see that on mine though I am on the 2012 version alpha. Can you post back with the firefox version and Mcafee version numbers. Try with netguard disabled is there a change?
Netguard is in the firewall settings
I am on Firefox 8.0 and
Mcafee SecurityCenter verion 11.0.623
Mcafee Virus Scan version 12.0.294
Mcafee Personal Firewall version 12.0.345
Mcafee SiteAdvisor 126.96.36.199
Mcafee QuickClean and Shredder version 11.0.393
and disabling Netguard didn't do anything. I had the regular version of mcafee installed and I was doing just fine. Is there anything added with plus that can cause this cause now even internet explorer is doing the same thing?
Do you have any other spyware/malware protection software? If so please un-install it.
It would be good to try updating the windows and re-installing the McAfee software