If you ask most PC OEM manufacturers its either a BIOS update or you are out of luck.
I know that alot of Dell systems I have are 50/50 some will do standby and hibernate with no issues, some will only do syandby, some will do nothing at all but turn off the monitor.
After speaking to Dell, they basically said it was on a per system basis...I would have to try it on each system.
I just dont use it now.....