Printer Problem Yet Again

I've asked this before and I shall try again to get an answer.
Boot up and do some printing using an HP660C.
Do nothing for, say, 1/2 hour.
After this "dead" time try and print something. I get an error message saying the printer is out of paper. It is not out of paper.
If I shut down completely and reboot and then request printing it prints just fine.
I've unistalled the printer and booted up
I've done this and then reinstalled using 98SE. I tried it again with a downloaded 660C HP driver. The same events occurr. No help.
Can anyone give me a clue as to how to eliminate this? Is there some other program such as a virus checker...(using Grisoft) that could be responsible for doing this during a "dead" time this?

 

Would you please explain what you have in mind with respect to the "Power Management" (sleep mode). Where would I find the answer to the question?

 

I found the Monitor was set to Never but the hard disk drive was set to 30 minutes. I set it to NEVER. The 30 minutes seems to really ring a bell. It fits the symptoms. Let's see what happens now. I will report back after trying this new setting.

 

I ran the test on the system. I printed something and then let it sit idle for 55 minutes. I then requested a print and it worked just beautifuilly. You are to be congratulated. I had asked many, many people for a suggested solution to this problem. You are the only one suggesting something that fit the evidence. Beautiful.
Thanks...tonight I will sleep much better.