Computer stuck entering sleep mode

Hello fellow Dell users,

I have posted on this forum before about the same issue regarding my Dell Inspiron 545 running Windows Vista 2007.  The problem is when I try to get my computer to enter sleep mode, the monitor says it enters power save mode but the computer itself is still active.  When this occurs, I cannot get the monitor to become active again and am forced to perform a manual shut down.  I downloaded a hotfix from microsoft that I thought cleared up the problem, but it began occuring with more and more frequency to the point where I cannot allow my computer to enter sleep mode at all.  I also updated the drivers for my monitor and other various things thinking that could be it, but my computer still has the same problem.  I am thoroughly stumped on this one, seeing as I can't find a single case other than my own where this is happening.  Any and all advice is greatly appreciated and I hope to hear back from someone soon.