I just had the same problem with my PNY 16 GB Attache (CE-FC) flash drive.
When I put it into my computer, instead of opening, it offered to "format" the drive.
Since I already have about 10 GBS of Files, Data, and Programs on it, I didn't want to do that.
Trying the drive in another computer that has read the drive before, got the same problem, but don't know why?
Is there any software that can "Fix" the drive, or at least allow me to Save the data to another drive?
Any other Help Assistance or Advise?
The reply from the PNY Techs was to "Re-Format" the drive, and forget about the data? Not the answer I hoped for. I did manage to go into Windows 7 disk management, and found the the type was no longer NTSF or FAT, but is not RAW? Not sure if that means much, except something has become corrupted? Still haven't found a retrieval software that may help to recover the data yet either.