Excel 2007 : Excel Not Responding Help

My office converted to excel 2007 about a month ago. When I leave excel open for several hours it will suddenly stop responding. It will even do this without any workbooks open. When I scroll across the excel button in my taskbar it displays a black screen. Has anybody else run across this issue? Has anyone found a solution to bring excel back to life. The only solution I have is to go to the task manager and terminate excel then reopen it. If I do that while I have a spreadsheet open I lose any unsaved work. Is there a better solution?

I suspect this is not necessarily an Excel issue, but could be hardware/software related to your PC configuration.

Try doing a general search on Google using terms: Excel 2007 stops working.

Most of the posts I've seen on this point to cause outside of Excel.

I suspect it might be a software/hardware issue as well. So far though I have not found the answer. I have googled many times with no results. All the other users I have found get issues while actively working in excel. In my case it seems to only happen when excel has been minimized or not been used for some period of time(30 minutes or more).