Windows 7: directory file listing goes blank

I was copying a few files from a directory with over 80 files to another drive.
When I returned to the orginal directory it was blank.
A check of properties shows 88 files in the directory.
Other directories on the same level are fine, the rest of the directories on the drive are fine.
This has happened before with another hard drive and I stopped using the drive.
I suspect this maybe is an undocumented feature of the NTFS of windows 7.
How can I see my files again?
They are still there.

Thanks
Broden