ATI Driver error causes sleep problems

My laptop refused to do anything after going to sleep. Buttons like caps-lock
would work (LED goes on), and the LED for power is also on. But it is
impossible to wake the laptop up.
When I turned it off and on again, Windows said an ATI driver error caused a
bsod.
I tried to update the driver from Windows Update, but the update failed
every time.
I tried to update the driver from ATI's website, but after installing it,
Vista refused to even start up (fixed with System Restore through Safe mode).
Can anyone lead me to the correct driver? I'm running 32-bit Vista Business.
Could the sleep problems be caused by anything else?