Stand By is disabled...?

Hello,

I've got this problem and I can't put my computer on to Stand By mode from anywhere:
Starting from Turning Off Computer window

and also from Control Panel/Power Options


As you can see I have Windows XP Pro., Athlon XP 1.8Ghz with 256mb RAM...
But, to make it clearly, the Stand By button worked before and everything was great!

The question is what happened and how can I fix it?

Big Thanks 4 helping, Alex.

 

Alex,
The only suggestions I have are, first make sure that the power management settings are enabled in the BIOS, and, I don't know if this affects XP, but it was a problem in W2K so worth looking at?

http://support.microsoft.com/default.aspx?scid=kb;en-us;257562

Make sure you are not using a standard VGA driver for your video card. In other words download the latest XP drivers for your exact card and install those drivers checking in the display properties that XP is using them.

 

Paul,

Yeah, thanks for the suggestion but I don't think I have a standard VGA driver.
My video card is Radeon 9000 Pro, and I'm using a driver called Catalyst 3.4. I tried to install the latest Catalyst Driver (3.5) but it says that I need to setup my video card for a standard VGA and then try to install again.
I'm really messed up here... Will it make any good if I uninstall the correctly installed driver and replace it with the new one?

Edit: I tried reinstalling the driver, made a little mess but it seems that I don't have a standard VGA driver. I have almost the latest driver for my video card, but not the latest I guess...

 

Looks like this problem could be caused by several issues. Since this list is quite lengthy and you'd know best which ones could apply to you. Here's a link to a good site that offers some causes and fixes.

kelly's korner:
http://www.kellys-korner-xp.com/xp_standby.htm

 

I was reading this section before and I never had the chance to find an answer to my problem, but thanks anyway.