Cable box keeps rebooting

I have a Scientific Atlanta Explorer 8240HDC box and it won't stop rebooting.  It happened the first time the other night and I thought it was a fluke.  Then it happened again the next day.  And the next.  And now it is happening every 5 to 20 minutes.  Has anyone else had this happen to them?  I tried having a reset signal sent and it did not help.  The last time I checked my DVR all of my recordings are gone.  The store is closed until tomorrow so I cannot exchange the box until then so I was hoping someone had some advice to tide me over.  It is not too hot, there is a fan on it and it is cool to the touch.  I think it is just a piece of junk...

HELP!