I recently upgraded my Dell Inspiron 660 with an EVGA 760 video card and a 500 watt EVGA PSU. Now, whenever I put it to sleep, it shuts off. I checked under power options, and it says it should be sleeping, but not. Any idea what caused this? My other systems specs are an i5-3330, 8 GB RAM, 2TB Seagate HDD.