there a file called neutrino.conf
/var/tuxbox/config/ --> neutrino.conf (this file is the heart of the IMG)
this keeps most of your setting i.e colour setting, passwords, /mnt (for recording) setting & a hell of a lot more. to many thing to mention
i always back this file and copy it in new imgs it save a lot of work.
hope this is of some help.
when you have copied it over always reboot.