This doesnt apply to XP. Sleep in vista isnt the same as standby in XP its a hybrid state where as well as going into standby it also writes to disk I.E hibernates. Theory being if it does loose power it will still come back up ok as if you hibernated. Trouble is its broken most of the time but is fixed in SP1. You can also set it up in the power management profiles. In XP the functions are split and you have the option to choose whatever one you want standby or hibernate. I am pretty sure you can also set the M2 not to hard off as well because loads of people use standby with XP which still needs the 5v.