Premiere Elements 12 - on what computer operating system?
Have you updated 12 to the 12.1 Update using an opened project's Help Menu/Update?
What are you doing in the program - DV or HDV Capture Firewire into the Premiere Elements 12 Capture Window?
If you are doing DV or HDV Captures, then you are putting DV AVI or MPEG2.mpg on the Timeline for edit. Is that what you are going?
Or are you doing something else besides firewire captures? If other...
What is the format of your video on the Timeline?
What are you setting as the project preset - please tell us what you see of
and the readings for Editing Mode, Timebase, Frame Size, and Pixel Aspect Ratio
Let us start here and then decide what next.