successful install of 10.6.3 on studio 1555 but.... :-P

so leopard was treating me pretty nicely however i decided to update to snow leopard. Its took me 2 days but ive manged to get it installed and working!

With one problem however ive got a ati mobility 4570 ¬_¬ which means i cannot change my resolution !

ive tryed forcing it using the boot.plist ive tryed graphicsenable=y and neither worked

im doing some searching round to see if i can prehapes solve this but i havent had much look yet

if anybody could give me some advice or point me in the right direction it would be really apreciated!

oh and if any of you guys have similar machines and want to get 10.6.3 running ill be glad to help !