My 2 cents worth:
- I take it the warranty's run out so no assistance from manufacturer?
- who is the manufacturer btw?
- is there anything connected to any USB at all - like a multifunction V45 HP show-stopper printer for instance?
- is it possible that Windows Installer is displaying a message when the monitor goes blank and it needs some sort of input from the keyboard like Enter or Yes/No - could try that...
- what version of XP 2001 or 2002?
amofw