It seems that mounting and unmouting of floppy disks cannot be done with the PCMan file manager if your floppy disk drive is not a USB device but a conventional one.

You could try the following.

Open a terminal. Insert a floppy disk with some files on it into your floppy disk drive. Create a mount point, load the appropriate kernel module and mount your floppy disk.
Code:
sudo mkdir /media/fd0
sudo modprobe floppy
sudo mount -o uid=1000,gid=1000 /dev/fd0 /media/fd0
Open a file manager and navigate to the directory /media/fd0. You should see the files on your floppy disk.

Before you remove your floppy disk you should close the file manager and issue the command
Code:
sudo umount /media/fd0
in a terminal.