Ted Pomeroy writes:
My routine is to suspend during the day, if I go out or take an hour off for non-computer work. Over night I switch off after saving work and closing all apps.
I do the same thing, though occasionally I leave it sleeping overnight, if I'm in the middle of something complicated with a lot of windows open, or if I just never got back to the machine after suspending it. With some machines, though, you have to keep an eye on them. My current Lenovo tends to randomly wake up a minute or two after I suspend it. If I suspend again immediately, usually it'll stay asleep the second time. My previous Lenovo didn't do that, but it would randomly come out of sleep hours later, so I'd go out for hours, come back and discover it up and running instead of sleeping. I've never had problems with non-Lenovo machines staying asleep, so I think Lenovo might just have something buggy in their BIOS that makes them wake up when they shouldn't. (Wake on LAN is disabled in the BIOS, and it happens when the laptop isn't even connected to a LAN, so it's not that.)
Your LXde is fine. I use Xfce4 or Mate, but the gui desktop is not the issue.
It actually could be, since LeRoy mentioned also closing the lid. Some desktops automatically sleep when the lid is closed, some might actually wake up if they're sleeping and see a lid switch event. I'm not sure if there's a reliable way to ask Linux "Why did you wake up?" after a resume. Debugging suspend/resume problems is hard. ...Akkana