Problems importing wav files

[Blastin]

I'm having problems importing wav files from external drive on my MDR. I select track/edit, import files, select, external drive, select wav file, this is where the problem begins, why are only some of the files show up, display, and others are not displayed. I attempted to import 10 wav files, separately, yet, only 8 wav files were there is there anyway to check files, the files show up correctly on the drive in MB or GB, but, some of the files won't show up on the file listing, why? Also, when I highlight, Rec/Ready, once or twice, two of the same wav files were imported.