I have just received my 3rd 1100MP.  The first two both had the same problem.  They would work for about an hour and then start turning themselves off.  The lamp light would come on for just a few seconds after it shut off and then the light would go off.  If you turned it back on then it would only stay on for 10-15 minutes and then it would turn off again, but no lights would light up.  A message was never displayed on the screen to let you know it was turning off.  It just went black.  I have checked all of the settings and eco mode is off and power save mode is off

 

The projector is mounted on a beam in the middle of a room and has plenty of ventilation.  The only thing that is unusall is that it (the building it is in) is at an elevation of 9000 feet.  It is connected to a UPS because at first we thought it was a power source problem. 

 

I have spent way too much time dealing with this projector(s) and just want a projector that works when we need it to.  We bought the projector in May 2005 and just received our 2nd replacement.