Using the ACM libary I write many programs that run in applets (I'm the author of the Free Java Book at freejavabook.org).
The applet that Dr. Java pops up has a menu bar at the top. This throws off the dimensions of the window.
If I write an expression to detect if an object is at the bottom of the window the expression only evaluates to true if the object is *below* the window by the height of the menu bar. So to make everything run properly completely within the window I have to throw in offsets for the height of the menu bar.
Can you eliminate the menu bar?