PC Comes out of Sleep Mode, but not Monitor

I bought a new PC 2 months ago. Since I had this PC I have encountered a repeated problem with the Sleep Mode per the Monitor. The PC and monitor will go into sleep mode, when the mouse is moved the PC comes out of sleep mode, but not the monitor. I have contacted HP support to resolve this issue with negative results. BIOS/drivers have been updated with negative results. Updates per HP pertaining to this problem have also been updated again with negative results. I even loaded all my programs one by one to make sure they are not the problem. I have reformatted this PC several times now. The PC and monitor work fine for awhile and then the problem occurs again. This last time I updated Windows Update by clicking the start button and then clicked on the button to put the PC in a low power state. It had the Windows Update icon which will install the updates and then shut down the computer. This morning I turned the PC on and the monitor was fine. Both went into sleep mode, but an hour later I came back and moved the mouse and the PC powered up from sleep mode, but not the Monitor. I am thinking it has to do with Vista. All drivers are working properly. Any information would help.

I have this same problem but as yet have not found a solution either. For me it doesnt happen everytime it goes to sleep. Just seems to be completely random.

well if you find a solution to this let me now. Still working on it myself and so far nothing is correcting the problem. If I find the solution will info u also. Turned my sleep mode off now and just using hibernation.