After the fix for 6711576 the new function is used to determine the bounds of a top-level window: if running on Vista it uses a DWM-specific method to retrive the bounds, otherwise it must fall bacl to the old method of using the WinAPI ::GetWindowRect() function.

However, the logic in the if(){} statement was broken, and the old method was never invoked. This caused the method to return garbage instead of the real bounds of the window on systems earlier than Vista.