Aqua-Soft ForumsI have had this problem once before a long time ago, and fixed it but do not remember how i did it. What happens is when i double click in the titlebar of a window to maximize it, it will maximize, but for some reason it thinks that my taskbar is at the bottom of the screen (and i have mine at the top) so it places the top of the window at the very top of my screen, and i get a blank space at the bottom of my screen where the taskbar defualt location is, and not at the bottom of my taskbar. The weird thing though, is if i double click the application on my taskbar, it will reset it to the correct position.
Titlebar goes under taskbar
strange, try maximizing a window and moving your taskbar or unlocking and locking it again.. although these might be pointless, they could work 
i just use styler's "window snap" option. but if you ain't using that, go with thisisepic's suggestions, bia
yeah when that happens unlock and lock your taskbar