If I understand the translation, you have either: (a) a system that is idling down and entering the S3 low power state or (b) a system that is shut down (in S5 power state) but has Magic Packet wakeup enabled. Regardless of which, when a magic packet is actually received from another system, the system starts to awaken but fails to do so completely. Is this correct?
My first question will always be: Have you verified that the latest BIOS and the latest drivers have been installed for the motherboard and all add-in cards?
For the S3 case, this is often a driver issue - one of the drivers is not restoring its hardware state correctly. The most common culprit is the video card. Some BIOSs have a capability for reinitializing the video hardware during a S3 restore. If you have this capability in your BIOS, try enabling it and see if this fixes the problem...
Sadly you havn't got a complete translation. In the initial post I wrote that the latest BIOS (ALB6510H.86A) is installed. All drivers are up-to-date. No cards are installed.
Could you please help me with the video card: I don't know where to find the needed BIOS-setting. I'm using the on-board video card.
I checked the AL BIOS; it does not have this parameter. But, this parameter only applied to add-in video cards, anyway, so would not have made a difference in this case.
Let's try to analyze which if the scenarios is taking place. Is the system idling down into the S3 low power state, into the S4 low power state or is it shutting down completely (into S5)? Magic packet can be used to wake from any of these states. If from S3 (suspend to RAM), the system just resumes (no BIOS screens seen at all). If from S4 (suspend to disk), a BIOS screen will appear (without hot key prompts), but it will be quickly replaced by the Windows Resume screen. If from S5, the normal BIOS screens (including hot key prompts) should appear...