I got the "other firmware p4p800se-deluxe" flashed succesfully using the socket from p4b533e motherboard by using the uniflash2.05b tool on a dos startup floppy made in windows xp.
Maybe in 'distant' future I can try flashing with a newer version of flashrom if I want to take risks... like maybe try a beta bios etc... but for a couple of weeks / months I keep it this way. Here is some output info for my board asked on IRC, I hope it will help you with the development of flashrom. Thanks for the support and input sofar. If you like I can also sent you output info of p4p800s-e "deluxe" which is fixed btw.