What computer operating system for your Premiere Elements 8.0/8.0.1?
You cannot import a Premiere Elements project file (.prel) as source media into another Premiere Elements project file.
To transfer the content from project file 1 to project file 2...
a. export the project file 1 Timeline content to file saved to computer hard drive, and then import that export into project file 2.
b. if you have Windows computer, do a copy/paste insert between projects...for that, please see
Please consider, and give more information. Any questions, please ask.