Please see bug report #606903 and attached screen captures. BTTB Ver. 2.9.0 window crops off interface elements at "large size" (120 DPI) and "custom" (> 120 DPI) font settings under WinXP SP2. I don't now what it is about designing GUIs under Windoze, but I have seen this problem in several software packages.
What is even more bizarre is that once the BTTB window has been maximized, BTTB subsequently opens in a "Normal Window" with mazimized dimensions.