if i remember correctly gpm is ur mouse server which gets loaded in the boot time...what u can do is either boot with a boot disk or try going into another console ctrl+alt F2 to F6 and see if u can get the console log in screen. Anyways after successfully loging in, change ur rc.4 script to load gdm or whatever login manager that works...i personally like gdm with that sunfloweron the bot right
so pretty