ps3 usb save game not reading

So since there is no new games on X360 recently I turned back to my PS3. I have been playing through The Last Of Us again and thought I would spice it up with some cheats ;-) I downloaded Brute Force and got it working (eventually) and have transfered a save file and added the cheats but when I try to put it back on the PS3 it says no saved files on USB? When I try to copy the save file again from PS3 to USB it says the USB already contains save data with that name, do you want to overwrite. So it must be there!!! Can someone tell me where I am going wrong?

Thanks