Sometimes you could go nuts: Having sent in an Acer TravelMate 7730G to the German Acer Support for replacing the mainboard, it turns out afterwards that the operating system does not shut down properly anymore. After some long time googling around you detect that this might be related to the driver of the integrated WebCam. The device manager reports it to be a “Acer Crystal Eye Webcam” wheras the manufactor of the driver is Suyin.
Many forums on the web recommend to reinstall the driver to fix the problem, however, that turns out to be not successful in this case. Only after I detected this post I got the important hint: it’s the point that the power management of this driver does not work well. By deactivating the power management of the USB root hub to where the camera is attached, you are able to fix the problem. How to detect the root hub in question is a bit more complex than stated at the post there: As the camera itself is a composite USB device, the hardware that is connected to the hub is not the camera itself, but the composite device. At the end you need to look out for an USB root hub where the composite device is attached to. After finding that fixing the problem was a piece of cake (see recommendation provided by the post mentioned above).