Sometimes (but not always), I use my laptop exactly like a desktop computer: I power it on with the lid closed and an external monitor and USB keyboard and mouse connected. When I later want to shut it down, the lid is still closed. It used to power down just fine with previous versions of Ubuntu (12.04 and 12.10 for sure, 13.04 probably as well).
Ever since I installed Ubuntu 13.10, instead of powering down, my laptop now goes to sleep immediately after logging me off. The actual shutdown sequence only happens if I open the lid again, otherwise my laptop stays suspended.
So I have been caught a few times with my laptop still on when I expected it to be off. Not a good idea to shove a running computer inside a closed bag that I carry around!
Searching around, I find a lot of people with the opposite problem (computer shutting down when they really want to suspend). I also read many people advising to make changes to some "systemd" setting to ignore the suspend altogether, which I am wary about: why would I want to disable suspend completely for a single type of situation while I still want my laptop to suspend when I use it on battery power? And even more since it used to work just fine with previous versions of Ubuntu.
Do you guys have any idea what the problem might be, or how I could troubleshoot this deeper?
I am left with an additional question: is this problem specific to my computer, have I done something wrong to cause it? As soon as I have time, I will try to work on this. Like, does this happen from the live CD? Does it happen on a different laptop computer? Does it happen with a completely clean install on my current computer? I will let you know what I find out.