User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2b1) Gecko/20091029 Firefox/3.6b1 Build Identifier: Firefox 3.6b1 whenever i have many tabs open i can see them all when i put the mouse over the Firefox icons but sometimes the icon is just a circle turning. I have also tried firefox 3.6b1 on another computers resulting in the same bug. Reproducible: Sometimes Steps to Reproduce: 1.Open many tabs and there is much likelihood of this occurring. Actual Results: I saw tabs with only spinning circle. Expected Results: I should seen all the thumbnails of the websites as normal. am using Chromifox Extreme but i do not think that has anything to do with the problem because i have tried other themes.