User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 Enlarging, or full size will not show the titlebar button, " X ", " _ ", ect., Reproducible: Sometimes Steps to Reproduce: 1. Go to wherever you may open Firefox Beta 2. Open it. 3. Enlarge by pressing the " box ". Actual Results: Just fit the screen showing the Closing buttons, and maximize, and minimize. Expected Results: A black box, covers where it is supposed to be.