[CentOS] poweroff when returning from standby

Hi,

I managed to make my Packard Bell EasyNote to standby (suspend to RAM), but I 
still have a problem: when I press the power button to return from standby, 
the system is restored but is immediately entering the poweroff procedure ... 
I don't know why. It's like I pressed the power button twice, which I didn't. 
Do you have any ideas of what could be wrong?

Thanks,
Adrian