I was absolutely sure that I always used to do

mount -o loop foo.iso /mnt/loop
&&
mount -o remount,rw /mnt/loop

But apparently there isn't anything to edit iso9660 images on the fly :/

Is this right? I must have been so mistaken.

I'm told that I have to copy it all back again with mkisofs; a pain since the CD `bootfile` matters, and a bigger pain because I only have 1gb free and I'm doing a 4gb DVD image.

Guess I'll just have to reboot into Windows and use WinISO :/

I expect the XBox people find this a pain too. And yes, I relise iso9660 was only meant to be read-only originally.