I would check via terminal if you can see the volume there. It should be possible by entering the following commands:
The last command should show you the rights on the left, even for invisible files. Always three digits show the rights for the owner, the group, and others. r means read, w means write and x means executable. When you use the chmod command, you can set the rights new. Enter the following:
Code:
sudo chmod 777 >insert your volume here<
777 sets read/write/execute for all users. I think that should solve it. But remember to adjust the rights later with repair permissions/batchmod!
Hope that helps