Somebody help me please, i need help for browsing with firefox in mandriva

I just finished installed Madriva free 2007 and set up internet connection. Lucky it's work but only in dns mode like http://202.22.3.33

for information i use static ip address : 192.168.0.55 and gateway : 192.168.0.1
DNS 192.168.0.2.

i also tried using DHCP to uncheck at their option like some thread inform before but the ip changed into 192.168.1.2 and gateway 192.168.1.1. and it did'nt work because my modem only uses ip 192.168.0.1. everytime i use automatically set ip the ip change into 192.168.1.1.

i use this LAN connection from my friend computer (windows). My friend pc connected to internet and he just attached to a switch to share internet connection. No problem in windows because same interface but i dun know with mandriva. can someone give a hint how to fix this. i need step by step solution because i'm totaly newbie.

if i use http://209.85.135.99 i can browse for google but if i click a link or make new tab it won't work. weird

*if someone know bout Yahoo Messenger that support in mandriva tell please