The password for Debian's root user should be the same as your Maemo root user, because my script copies the user info from Maemo. (Just checked; it works...) Beware that if you have an N800 and you try to run Synaptic in IceWM, you will need a hardware keyboard to enter the admin password.

Perhaps you shouldn't bother trying to do that stuff in IceWM; after all, just press the "Home" key (with the house on it) to get back to OS2008. If you run the "Debian chroot" from your menu, it drops you to a root prompt in Debian. Also, the "Synaptic Package Manager" item from the menu gives you root access without a password.

EDIT: Bun, you changed your post after I replied! Cheater!

EDIT2: I just checked, there's a passwordless root terminal in IceWM under Programs / Applications / Terminal Emulators called "X-Terminal as root (GKsu)"