I'm running Ubuntu 12.04 on a Toshiba Satellite A70. By the way, it supports hibernation from Ubuntu.
When I suspend (either with the menu or the power button), the laptop enters suspend and stays that way.
However, 50% of the time, after it resumes, it will go back into suspend after 30 seconds. Once I resume it the second time, there are no more suspends till I request it again.
Suspension works normally on Windows XP.
What is the problem?