Mounting a FreeBSD USB Memory Stick Image rw

["Martin G. McCormick" <martin@server1.shellworld.net>]

	Is it possible to mount the FreeBSD USB iso image on a
debian system? I need to edit one of the configuration files and
the nearest USB port is on a Debian system. The hope is to add a
line of text to a file, transfer the image to a USB drive and
boot the FreeBSD system from the memory stick for an
installation.
	I did try
mount -t ufs -ro loop FreeBSD-9.1-RELEASE-amd64-memstick-headless.img /mnt
first to see what would happen and it appeared to work but ls
/mnt throws an I/O error as does any operation on /mnt until one
umounts /mnt.

Thank you.

Martin McCormick