Several Alienware M18x users are complaining about the nasty Aero issue in which the Windows 7 randomly switches back to Basic interface which is non transparent, from Aero which is transparent. Exact reason behind this is still unknown.
Interestingly, this issue is happening with the M18x irrespective of the hardware configuration. Even more annoying – it happens even when you are playing a game or while running GPU or processor benchmark to evaluate performance of the notebook. [via forum.notebookreview]