The computer immediately powers up again after entering the sleep state.
Known to apply to the following Sophos product(s) and version(s)
SafeGuard Enterprise Device Encryption as of version 5.50
Windows Vista, Windows 7
This behavior can be caused by external USB devices (e.g. USB Hubs). It seems that the power loss of the USB Device triggers a USB event that causes the PC to wake up again immediately.
A similar issues with Windows Vista is described in a Microsoft knowledge base article (Article ID: 935267) .
What To Do
As a workaround do one of the following:
- Disable "wakeup by USB" in the BIOS (if possible)
- Change the power supply source of all USB ports from 5V to 5V standby