Ubuntu 6 network problem

[b&p]

Hello there: I've just installed Ubuntu on my hp laptop. The initial 
install was fine. However as soon as I connected to the internet, 
throught a b/band router it told me there were 128 updates waiting. So I 
let it do all the updating. And then it asked for a restart and when I 
did that....no more internet. I've tried all the networking gui's and 
they say the NIC is active but it won't connect to anything. I can't 
ping anywhere except localhost either. Can someone offer some 
suggestions, please?
Thanks
b