Ok so they import and play fine for me on linux and Matt on windows.
What I like you to try doing is to delete all of the files imported as Data in MC (just choose the option to remove them from the database).
Then create a new SmartList under playlists.
Call it "Bad or Removed"
Set the Media Type is and check all of the possibilities (Audio, empty, data, etc)
Then under Modify Results
Limit Database to
choose Removed and Bad
and hit Ok.
The smartlist will be created that has all of the inactive database entries in it.
Ctrl-A on that to select all and hit delete
Refresh the view and do it a second time if there are still some there.
Now that the database has those cleaned out, try the import again. If you are using auto-import you can just run the auto-import otherwise import a specific folder.
Note that if there are other files in a specific folder that you have already imported you'll want to use the option to not reimport them otherwise you'll end up with dups.
Report back!