cannot access to internet from inside

[banalas]

I have pix with 3 interfaces outside,indise and dmz
i can go the internet from my dmz and access all websites
but i have strange problem, when i access internet from inside few sites i can get to the web page and few sites it goes to google seach engine or msn search and it says there is no domain name , but if i try the same web site from dmz it works,

can some one please help a

and some help with debug syntax to check the http packet
going through pix

Thanks
Sridhar