Movie won't run in movie editor

I am very new to all this. I just bought a Sony camcorder and a sony DVD burner, which came with a Nero package that included Nero express 3. I have been able to capture the video with no problem. But when I try to edit it the movie on the little edit screen skips through the movie with still pictures. If I play the file with Nero showtime the movie plays fine or if I burn the captured video the way it is, it plays fine on the DVD I burn. When I try to add chapters it skips the same way as in edit. Have I go something set wrong? My processor is running at 1.6 and the computer has 512 RAM.