Thank you all for you answers
@ wojox: I did, but nothing is useful.
@ forestpiskie: the UUDI is the same, here is the output of both commands:
@ plucky: I had the same UUID too.
/dev/sda8: UUID="721282a7-a88d-4ea5-9b75-b527f47835a6" TYPE="swap"
#UUID=721282a7-a88d-4ea5-9b75-b527f47835a6 none swap sw 0 0
@ QLee :
I didn't understand everything you said
Is it that ACPI hardware support is an alternative to software support ?
What do you mean by "restore the options to the menu" ?
No, the problem didn't happen after an upgrade. It happened after a while of fresh install.
How do I purge the hibernate package?
I think this could be useful: here is the output of "free" command after opening A LOT of programs:
total used free shared buffers cached
Mem: 2057832 2037976 19856 0 15028 198236
-/+ buffers/cache: 1824712 233120
Swap: 0 0 0