Handycam movies incompatible with Adobe Premier Elements?

After filming movies on my Sony Handycam (Model#DCR-DVD650), the movies are stored on the video camera's memory card. After exporting the movies to my computer, they are (by default) saved as Mpegs. But for some reason, when I attempt to add them to an Adobe Premier Elements project, the program won't accept the movies. A window pops up, informing me - 'Unsupported Audio Rate in File.' I originally record these movies, from the camera, using HD and they look great. But in order to use them in an Adobe Premier Elements project I have to convert them. Then, when the project is done, I attempt to render them in the highest quality possible...but there's still diminishment. Finally, when the movie is uploaded to Youtube, there's further loss of quality. So the movies, right out of the camera look wonderful. By the time they get to YouTube, people ask me to film them in a better quality. Any idea why an Adobe Premier Elements doesn't accept the original file? Any recommendations? Thanks in advance.