Unwriteable files

I've been using a Sony digital camera with a floppy. Whenever I download the pictures into their file, they become unwriteable, which means I can't see them in Gimp. So far I've had to do chmod a-w *.* and then chmod u+w *.* every time. (ps: I could be remembering the command incorrectly here because I lost the instructions that I was given. I will research and update it. Whatever it was, it worked at the time.)

Why is this happening?

Also, I've had to umount /mnt/floppy and then mount /mnt/floppy before the computer will read a new disk of pictures. Is this normal?

crossposted to linux, linuxnewbies, and techgirls