User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:184.108.40.206) Gecko/20101026 Firefox/3.6.12 GTB7.1 ( .NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:220.127.116.11) Gecko/20101026 Firefox/3.6.12 GTB7.1 ( .NET CLR 3.5.30729) The first tab (the one that automatically opens when you open Mozilla Firefox) doesn't close when you press the "x" button (the small one located on the tab itself). However, it will close if I hit the small "x" button, open a new tab, then close the new tab. This results in exiting out of both tabs and leaving me with an "untitled" tab. I have no problems with any tabs after that. This only started happening when I upgraded to Firefox Version 3.6.12. Oddly enough, the original tab doesn't have a website address either. Reproducible: Always Steps to Reproduce: 1.Open Mozilla Firefox. 2.Press the small "x" button on the tab. 3.The window doesn't close. To find out how to fix that, read on. 4.Open a new tab. 5.Close the new tab. Actual Results: If I stop on step 3, it doesn't close. If I stop on step 5, both tabs close, leaving me with one new blank tab. Expected Results: For step 3, it should have exited out of the original tab right away. I've recently added Mozilla Firefox Version 3.6.12. I've cleared my history several times (that includes cookies). Some of the Add-ons that have been given me trouble before are: Destroy The Web (Version 1.1.1). Add-ons that are probably related to this problem include: Fast Close Tabs 1.3, Personas 1.6.1. However, Fast Close Tabs has not had any updates for a while, and I've had it since I first got Firefox, so I don't think it has much to do with the problem. The browser doesn't crash whenever the bug happens. My homepage is Google.com.