suse linux 10.1 i can't get internet using dhcp or manual

i need help with suse linux 10.1. i have linksys wireless router wlan B and buffalo airstation ethernet converter turbo G. i use it with windows xp and is fast and smoothly. but i set up linux in manual and auto mode dhcp and it recognizes the ethernet0 good but internet doesn't connect at all. i tried everything but nothing come up.
both system are in the same computer and work good.

buffalo ethernet converter is a device that mimic "real" ethernet ports like if you're connected directly from your wireless router's ports. there's no drivers need or extreme settings. in others words, is a wireless ethernet bridge.

linux connect and recognizes the pc ethernet card, and the buffalo connection. but when i tried to ping the buffalo ip address, linux shows " unreachable host" and from kde browser konqueror or mozilla firefox is the same problem. i can't reach the buffalo ip settings or linksys ip settings like i do in windows.

manual settings in linux:

ip address : 192.168.1.20
subnet mask : 255.255.255.0
default gateway : 192.168.1.1 ( linksys router )
dns settings : ( from my provider )

auto mode dhcp:

ip address : 169.254.194.162
subnet mask: 255.255.0.0 ( this is not good, because i need 255.255.255.0 )

windows get easily the "real" ip conf setting from linksys in dhcp mode:

ip address : 192.168.1.122
subnet mask : 255.255.255.0
default gateway: 192.168.1.1

i test different ip, different ways from Yast. but every attemp failed.

if you know how to solve it, please let me know.

my hardware info

OS : suse linux 10.1
computer : hp pavilion a1483w
processors: dual amd athlon 64 X2 4.2 ghz
ram : 2 gb
HD : 260 GB
video : 256 mb