Sleep, hibernate: wake up! (& bluetooth)

I have bought a new laptop which is running Windows Vista on it. Usually it goes into sleep mode in the night and I am not able to wake it up again? When I press any keys on the keyboard or touch the touchpad, nothin happens and even when I touch the power button then the laptop reboots. I am able to use the Media Direct button but I dont want to use it. It also looses bluetooth connection when it goes into sleep or hibernate mode and therefore I have to restart the laptop again. I get this follwoing error under Bluetooth devices >> Hardware - "Dell Truemobile Bluetooth 355 plus EDR, Windows has stopped this device because it has reported problems code 43". Does anyone know about this problem?

The kind of problem that you are getting, occurs on a system in which a Bluetooth device is connected through a universal serial bus (USB) connection. To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base: http://support.microsoft.com/kb/935791