User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101203 BetterPrivacy-1.47 Firefox/3.6.13 (.NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101203 BetterPrivacy-1.47 Firefox/3.6.13 (.NET CLR 3.5.30729) With McAffee Site Checker 3.3 enabled Frefox freezes Reproducible: Always Steps to Reproduce: 1. Enable McAfee Site checker 2. Restart Firefox 3. Firefox freezes Actual Results: Firefox freezes Expected Results: Firefox shouldn't freeze

Please report to Mcafee, they need to updates their addon to support Firefox 4 fully.

Latest version of McAfee sit checker downloaded 3/5/11 appears to solve this problem.

Please can you confirm what version it is? See the about:support page (type in address bar) and paste the version/ID string. Thanks :-)

3.3.1.125_p1

Thanks for the version :-) (Older, non-working versions are going to be blocked here: Bug 621833)

Reopening since now in the McAfee section, so something for them to sort out.

Installed the latest version of Nightly (linked below) and McAfee SiteAdvisor 3.6.0.126: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2013-03-06-03-10-12-mozilla-central/ Enabled/Disabled McAfee SiteAdvisor several times and restarted the latest Nightly without any issues. Received no crashes, hangs or performance problems when using the browser. Also attempted Andy's steps several times without any crashes. Andy, can you reproduce the issue using the latest version of the Nightly build?