check the outputs on your power supply ..if the 5 v is fluctuating ( not always giving out a full 5 )either doze wont initiate fully or can shut down on user logouts ..

thats not the only thing that might be doing this ..but it is one of the most frequent causes of doze not fully switching on ..or switching off when doing something else ..

power supply fluctuation to the MOBO and faults ( slightly less voltage than required ) can also give some very weird behaviour from the USB ports ..whilst all other MOBO functions are unaffected ..

boot to "safe" and check the figures ..keep testing them for 30 minutes or so ..or swap the power supply for another and see if it helps ..( if it's overheating..can cause it to give out unstable voltages ) .. you may just need to swap its fan

edited for clarification

[edited by: Leosghost at 10:34 am (utc) on Aug. 31, 2006]

As a matter of fact I just had to replace the power supply because after cleaning the machines inside it didn't start up anymore (no I didn't use soap and water). However with a mint-condition power supply fresh out of the box, the weird shutdown persists.

The regular questions:

• Did you add or remove hardware recently? Try the "old" configuration.
  
• Have you tried to remove and reinsert the RAM? Sometimes after opening the computer case and touching the RAM contacts are not 100% OK. Reinserting the RAM helps is my experience.
  
• Remove and reinsert PCI cards and disk cables (although less likely than RAM problems)
  

If this happens 100% of the time, check the Registry. HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Shutdown contains a LogoffSetting and ShutdownSetting. The following values are valid:

• 0 - Log Off
  
• 1 - Shutdown
  
• 2 - Shutdown and Restart
  
• 3 - Shutdown and Power Off
  

I hope it isn't your reverse proxy... ;)

It's the new interns machine. What puzzles me is that there are TWO accounts on that machine, but the shutdown-upon-logoff only happens on ONE account (the freshly created one).