If I have the safari window in a secondary monitor, and I use the "maximize" button, or click on the title bar, it expands off my monitor so that the title bar is no longer accessible and I cannot move the browser window back into a viewable area. The only way I've found to fix this is to open a new safari window (if only one window is open), and right mouse on the Safari instance in the task bar, and use the "cascade" command.
This also happens for me- with safari 3.0.3 (522.15.5) Using Windows XP
Thanks for the bug report! Since this is a Safari bug (not a WebKit one), http://bugreport.apple.com/ would be the right place to report it. However, this is already in Radar <rdar://problem/5131696>, so you don't need to file a new report.
*** Bug 14947 has been marked as a duplicate of this bug. ***