User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1 Build ID: 20110928134238 Steps to reproduce: Switched on/off tab groups view and rearranged some tab groups. Actual results: Previews in some tab groups does not correspond to web pages (some previews are duplicate). Expected results: Previews should display correct web pages.
Probably related to bug 659278. Please try the nightly.