Resume problems in Toshiba Satellite A50

Hi people
I need y'all's help again!
I've got a new Toshiba Satellite A50 laptop. It came with Windows XP Sp1 preinstalled....as I like to keep up with the latest updates, i installed sp2 on it. the system works great...and real fast...but i encountered a problem when I upgraded. The system, when it now goes into standby or hibernate refuses to come back on. I mean...when i press the power button, the hard drive comes on and shows some activity....but then just stops....with the LCD blank. The first time this happened...a blue screen came up showing an error with my HDD....i switched it bak on...ran CHKDSK....and it repaired the HDD....but now this just happens without any errors.
In fact...a couple of days ago...it began to work normally....resuming properly...but then windows update downloaded something....and its doing the same thing again. I am using
Toshiba Satellite A50
Pentium M Processor 1.5GHz (Centrino Tech.)
intel 82855Gm chipset with integrated graphics (64MB memory)
256MB DDR RAM (PC2700)
Windows XP Pro

I tried upgrading BIOS, and downloaded chipset utility...but nothing will work.
u guyz have any ideas on this one??
Thanks
hohoha

Check microsoft.com for sp2 laptop hibernation issues.