I also upgraded from 12.04 to 12.10 and I had the same problem.
# Add a folder sudo mkdir /media/USERNAME
# assign the folder to my user sudo chown USERNAME.USERNAME /media/USERNAME
/media and other folders and directories are owned by root
/media/username is owned by username [drwxr-x--] User: username - Group: username
Worked for me to, thanks!
I also upgraded from 12.04 to 12.10 and I had the same problem.
# Add a folder
sudo mkdir /media/USERNAME
# assign the folder to my user
sudo chown USERNAME.USERNAME /media/USERNAME
/media and other folders and directories are owned by root
/media/username is owned by username
[drwxr-x--] User: username - Group: username
Worked for me to, thanks!