D630 wakes itself up - aka the haunted latitude

So I have a latitude D630 running Vista that works fine, falls asleep and wakes up okay, etc. But if you leave it sleeping for about 18 hours you can hear it try to wake itself up. So I checked the usual suspects in bios, wake on lan was off, system turn on timer off, etc. I finally found the culprit to be hibernate. The laptop is set for high performance power mode which by default sets hibernate to occur after the laptop has been 'sleeping' for 1080 minutes. And of course, there's no GUI option to turn off hibernate in Vista so back to the old trusty command line.

powercfg.exe /hibernate off

I don't use hybrid sleep mode or any of those fancy functions so turning this off saves me disk space and the peace of mind knowing that the laptop will not try to wake itself up at a bad time and choke to death in a laptop bag.

For more info on turning off hibernate and turning it back on -