User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8 (.NET CLR 3.5.30729) When resizing the browser window smaller, the Navigation toolbar shrinks. When it can no longer get any smaller and the user continues to resize the browser, the entire window is truncated. This includes the main content window. This means that the right scrollbar will be truncated and the user cannot scroll. Reproducible: Always Steps to Reproduce: 1. Use Windows XP (not tested in other operating systems) 2. Set the theme to Windows Classic 3. Slowly resize the browser smaller horizontally Actual Results: The browser window is truncated, including the right scrollbar. Here is an image of the the scrollbar beginning to truncate: http://img362.imageshack.us/img362/4596/partiallytruncatedscrol.png Here is an image of the completely truncated scrollbar: http://img362.imageshack.us/img362/4503/fullytruncatedscrollbar.png No navigation toolbar means a normally functioning scrollbar: http://img362.imageshack.us/img362/5920/nonavigationtoolbar.png Expected Results: When running on XP using the normal XP theme, the browser either refuses to resize any smaller or continues shrinking but truncates the Navigation toolbar, continuing to shrink the main content window appropriately. When the Navigation toolbar is turned off, there is nothing preventing the browser window from shrinking properly and the main content window is not truncated.