The file is missing a namespace declaration for itunes. To add one you'll need to determine the URL to the related schema.
Honestly, I've never had much luck with the Export/Import plugin. Rather than trying to debug the problem, I've resorted to copying the DB using phpMyAdmin with the default SQL format. Going this way, you do need to do a search and replace of URLs, but several different options exist to do this. I've always used the Interconnectit script without problems.
This is all covered in Moving WordPress. You'll want to clean out old cruft from the DB before exporting. You don't necessarily need to copy the entire DB, you could just copy posts and posts meta if that's all you want. This is assuming you've created a virtually empty DB through the install process. If you want a true clone you'll need to copy everything.
