I noticed a small problem with ROS's calculator; it was missing 8 pixels from the bottom in both normal and scientific modes. This lead to the calculator appearing chopped off at the bottom and looking rather bad. Here is a small patch fixing it.
Grant A. Brady A.K.A bragr
p.s. Here is the unmodified ROS calculator compared to Microsoft's on Windows XP: http://wtmfp.boldlygoingnowhere.org/calcs.png