Open up your favorite text editor as root, and edit /etc/fstab
Comment out the line that mentions your floppy device. For example, here is mine after the fact:
#/dev/fd0 /media/floppy0 vfat users,noauto 0 0
You may now mount your floppy. (If it doesn't show up in nautilus, type the following into a terminal: sudo mount /dev/fd0 /media/floppy0) (If that reports an unknown filesystem, then type sudo mount -t msdos /dev/fd0 /media/floppy0)
If you ever need to delete a file from the floppy, it is best to press Shift + delete rather than just pressing delete. This will permenantly remove the selected file(s), rather than sending them to a trash bin hidden on the floppy.