User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0 Build ID: 20130409194949 Steps to reproduce: While trying to error-check setup for a previous bug, I noticed that the Tab-bar and Munu-bar placements swap depending on if I use Win-7 'Classic' or 'Aero' themes. Actual results: Using 'Classic' theme, the Tab-bar is placed underneath the Menu-bar. Using 'Aero' themes, the Tab-bar is placed above the Menu. During my testing, no settings appear to have been altered except the Windows theme. Expected results: The Menu and Tab bars should remain consistently in their relative positions in the main TB window, regardless of which Windows theme is being used.