Power Options

I have an HP laptop using Vista SP-2. Until recently, the power settings
worked the way I set them (especially shutting off the display after 15
minutes of idle time). Now, this particular setting doesn't work (the
display stays on all the time). I haven't checked the other settings
yet. Tried Google but couldn't find anything that applied. Suggestions
for a solution?

Sorry, but I tried to cross-post to two groups and NEITHER group posted
my message. So I posted them individually.