The video editing program is Premiere Elements, not Photoshop Elements, although they are often bundled together. PRE has its own forum (very few of us here use it) and you'll get better answers to video questions over there. I'll move this for you.
What format and resolution is your video file?
How did you get it from your camera to your computer?
Do you have Premiere Elements 11 as well as Photoshop Elements 11?
How are you importing your video into Premiere Elements 11 (assumed Windows)? Add Media/Files and Folders/Project Assets? Or are you moving it from the Elements Organizer into the Premiere Elements 11 Expert workspace? Does the video play back OK on any of your computer players (Premiere Elements not involved)?
Bottom line may very well be a problem with the availability of the MotionJPEG video codec to Premiere Elements.
The 3 remedies that one frequently sees:
a. file conversion
b. download, install of MotionJPEG codec
c. grabbing appropriate codec from a camera utility if the camera has such a utility.
Please review and let us know if you have any further questions.
Add On...I did not see SG post in your thread until after I had posted this reply. Please respond in to his questions and troubleshooting first.