User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:36.0) Gecko/20100101 Firefox/36.0 Build ID: 20141212004002 Steps to reproduce: (1) Open up several tabs. (2) click on a tab that is not selected. Actual results: Occasionally, half of the browser view will display page content from the old tab. Sometimes when that happens, the browser will be unresponsive for several seconds, as well. Expected results: Firefox should immediately display page content only of the selected tab.

I just forced a FF crash. Here is the link to the report, if that would do any good (some 10 mins after the screenshot was taken):https://crash-stats.mozilla.com/report/index/2274cbd2-6d4a-466a-b44a-e97952141212

Can you go to about:support and copy the raw data from there, and paste it as an attachment at https://bugzilla.mozilla.org/attachment.cgi?bugid=1110696&action=enter (click the "paste text as an attachment" link at the top of the form to get a place to do so) This looks like a graphics issue similar to bug 1108499 to me...

The last time this happened was a day or two ago, but I hadn't noticed it for quite a while before that....

Looking on screenshot and description it's definitely a duplicate of bug #1067470.