The Disk You Inserted Was Not Readable By This Computer

Hi guys,

I have a small USB stick that I used to record music, im sure I stopped and ejected the usb correctly. I inserted the USB into the mac, and opened the USB as normal to get at the file, when I went to move the the file into iTunes I had an error message. Iv done a bit of troubleshooting but im a complete novice at all this.

Iv inserted the USB a few times and sometimes it the drive shows up and I can enter it but once I try moving the files I get the error messgae of "I didnt remove the drive correctly" Iv tried looking in Disc Utilites, the drive shows up (Doesnt show in Finder though) but I cannot repair. I also just spent X amount of $ on Disk Warrior, and again sometimes, the drive shows up, but other times it doesnt. When it does show up, it wont let me repair.

Clearly the file that im trying to get at is there but I cant access it! Please help!!