As part of my ongoing attempt to fix the niggly problems on my PC:
When I had Windows 98, pressing the Power Button on my PC case shut down windows gracefully, and turned the power off. I seem to remember settings which could change this to a hibernate mode, but I never used this option.
I am now on XP Pro, and the Power Button just seems to cut the power, without shutting down Windows. When I boot-up again, I get a warning that I did not shut down Windows properly.
This is not a problem if I shut down the PC from within Windows, and this is what I have been doing for the last few months. However, I'd still like the Power Button to shut down windows and turn the power off, like before.
Have just checked settings on my PC and as yours in Power settings it is on Shutdown so tried it and it shut down as it should. Try changing from 1 option then back to Shutdown see if that does anything.
Hmmm - It appears I made a duff suggestion earlier - in my WinXP Pro - having the power options set to Shut down, it always shuts down correctly, irrespective of how i have the power button set in the BIOS.
The only thing I couldn't try - disabling ACPI in the BIOS made the system hang on start-up - so I don't oknw what effect this should have.