Hibernation problem - power managment

I have Hibernation problem ,
I using fedura core 2 on IBM platform.
the problem :
the computer get to sleep after some time and I can't wake it.
1. If I connect it on remote I can use it ( just the monitor show nothing).
2. It's happend only when I log on. if it on login screen it's alright (get to sleep and wake up when I touch keyboard or mouse ).

I think I tried almost everything ( try to cancel power managment totaly , try to turn of AMP and/or ACPI .

please help ....
thanks