Comment 4 for bug 778595

Here was my experience with dragging it to the top:

If the application started up maximized, it seems to work, but after enough times (maybe 20 or so), it would eventually stop maximizing correctly. If the application wasn't maximized at startup, if would stop maximizing correctly after only 5 or 10 times. It also seemed to work a better percentage of the time if I maximized/un-maximized by repeatedly dragging the title bar to/from the top without letting go of the left mouse button.

It would stop maximizing correctly sooner if you minimized the window OR if you un-maximized the window by double-clicking the title bar or clicking the un-maximize button.