User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b11) Gecko/20100101 Firefox/4.0b11 Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b11) Gecko/20100101 Firefox/4.0b11 When loading a Google Search, Firefox silently hangs and the loading image doesn't stop. Can be closed fine, however it then requires the use of Task Manager to kill the process otherwise it's still running in the background and future loading attempts of Firefox display the 'running but frozen' message. Reproducible: Always Steps to Reproduce: 1. visit http://www.google.com 2. type in a query of your choice 3. watch it hang Actual Results: It hangs Expected Results: Loaded the page gracefully Default theme No addons

Turns out it's any search engine www.bing.com www.ask.com www.google.com etc

Mozilla/5.0 (Windows NT 6.1; rv:2.0b12pre) Gecko/20110210 Firefox/4.0b12pre Works fine for me. Please try if it works fine by creating a new profile. https://support.mozilla.com/en-US/kb/Managing+profiles#Creating_a_profile.

Nope, still doing it :/

reinstalling the BETA did it - don't know how, but it did:D

Has started to happen again; tried clearing out cache and deleting my Firefox profile to no avail.

I can confirm that the McAfee Site Advisor causes this bug; suggest disabling it; makes browsing impossible due to the nature of the bug.

Dom: Can you please post the extension section from about:support (enter as URL in Firefox) in this bug. We need the exact version information for this addon.

We're now tracking such bugs. This doesn't mean it's something we can fix, merely something we hope to be able to point vendors to so they can investigate. This is an automated message.

Went through the issue using the following builds/versions: - latest Nightly build available here: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2013-03-10-03-09-06-mozilla-central/ - McAfee SiteAdvisor 3.6.0.187 - Windows 7 Home Premium SP1 x86 - Used Google and searched several terms without any issues (selected some results without issues) - Used Ask and searched several terms without any issues (selected some results without issues) - Used Bing and searched several terms without any issues (selected some results without issues) - Used Yahoo and searched several terms without any issues (selected some results without issues) Dom, can you reproduce the original issue using the latest version of Nightly & McAfee SiteAdvisor?