You will never guess, don’t even try it. Here is the article that made Frans Bauma sad. Very very educational, highly recommended read (assuming that it is correctly written).
But what’s even funnier is that none of those Sleep/Hibernate/Hybrid Sleep options work for my pretty decent new computer. It goes to sleep/hibernate/hybrid sleep but then immediately returns to normal functional state for no apparent reason (anybody knows how to pinpoint the source of the problem?). I guess they would have to duplicate the effort spent on sleep feature.
Maybe you have “Wake on lan” feature set in the BIOS. It is usually configured to wake the computer only when so called Magic packed arrives at network card, but can be configured to wake on any network packet. Disconnect your computer from LAN/Internet and then try.
UPS, i.e. uninterruptible power supply? ๐
Petar: I tried unplugging network cable and it worked as it should (computer remained in sleep state). But then I plugged in network cable and it worked, too. After some further attempts through the day is stopped working again (with network cable). I’ll test more.
Milan: ๐ Actually my computer is on UPS.
Petar: Looks like network cable is a real culprit. Not sure how to turn it off though as I think I’ve already disabled WOL in BIOS.