Ubuntu – Network manager doesn’t find the wired conection

There is no problem to connect to my wireless network, but when I want to change it to wired connection the manger can't find the connection.

There is green light in the socket when I connect the cable. So how can I fix this problem?

I am using ubuntu 10.04 netbook version and my computer is a HP mini 2140.

Thanks for any help 🙂