Almost UP

Hello everybody!
I'm quite new to linux (I installed only once when Redhat was not born yet:)
I have Mandrake 9.1 and a USB SURECOM EP-9001 wlan adapter...
I used the drivers at berios (the ones on sourceforge didn't work) and 
*ALMOST* worked fine...
This is what I see when i run iwconfig:

lo       no wireless extensions.
wlan0 IEEE 802.11-DS ESS-ID:"WLAN"
          Mode:Auto Channel:1 Access Point: 00:08:A1:42:94:A8
          Bit rate:11Mb/s
          RTS thr=1536 B Fragment thr=1536
	Encryption key:off
	Power management:off
	Link Quality:0 Signal Level:105 Noise level:0
etc...

If i run ifconfig:
lo etc etc. omissis
[...]

wlan0	link encap:Ethernet HWAddr:00:08:A1....
	inet addr: 192.168.0.5 Bcast:192.168.0.255 Mask:255.255.255.0
	UP BROADCASTING RUNNING MTU:1500 Metric:1
	RX Packets.... etc

It seems to be up and running but if I ping every othe pc in the net it 
doesn't work! Even if i ping the router (192.168.0.1)
Why? Do I have to config something else??
Do the card work fine?
I'm not sure of the parameters of the card but it configured automatically 
so I think they're correct!

HELP ME!!!

Cheers,
Alberto