This is weird. Just recently - last day or two - all my flash drives are coming up as read-only. I have seached for solution and tried them all. Re-partioned, re-formated and chown - all with no success. I have tried right clicking on the drive and going to properties and then changing the permissions - and it reverts back to read-only. I thought maybe the port on the front of the machine were causing the issue, they are not, it is all ports. I always safely-remove trhe drives from my system, so it can not be "locked".
Just tested and portable hard-drive that has been in no other system for a while and same thing. I should mention that one of the flash drives have been in my XP laptop, my blue-ray player, my sons PS3 and his win7 machine. But the other USB drives have not. And this has been an ongoing pratice of multiple machines for the last 5 years with no issues.
The chown comand I used is - sudo chown -R myname:myname /media/name-of-drive gives a reply of "chown: changing ownership of `/media/4GB-CRUSER': Operation not permitted"
Also tried sudo chmod 777 /media/4GB-CRUSER with no success.
I am running Mint 13 with Cinnamon.
Some input or advise would be appreciated. I use these everyday and it seems odd that this would happen all of a sudden. One thing that I am not sure has anything to do with this - it started after the last update I did a few days ago.