What is the difference between suspend by closing the laptop's lid and clicking Logout\Suspend

[Athlion]

Hello all!

I'm having a problem with my laptop where if I suspend it by using the
Logout\Suspend button everything works flawlessly but if I suspend by
closing the lid, I get a failed suspend after about 24 hours and I am
trying to track it down. Since I don't have much knowledge on the
internal workings of the ACPI subsystem, can someone inform me on what
is the difference in terms on what gets executed and by whom in these
two situations? Shouldn't these two be equivalent? Obviously, they
aren't, but in what respect do they differ?

I'm running Arch Linux and XFCE 4.10 on a Lenovo T420.

Thanks!!

P.S. Regarding the problem, there is a thread on Arch Forums should
someone need to look deeper:
> https://bbs.archlinux.org/viewtopic.php?id=144381