More information needed for someone to help... please click below and provide the requested information
-Premiere Elements FAQ http://forums.adobe.com/thread/1042180
Such as... Windows or Mac and which version... graphics adapter (ATI or nVidia or ???) and device driver version... as a start of the needed details
Using iMac 10.7.5 3.4GHz intel Core i7
8GB 1333 MHz DDR3
Upgrading from PE10 to PE12
Don't remember if it's ATI or nVidia, (how can I find out?), PE10 works fine.
Nvidia cuda Driver version 5.0.36