Thanx for reply!
I think the problem is with the computer.
I also tried xubuntu live CD and pppoe-discover fails.
On three other computers (XP, Vista and ubuntu) it works on the same network port…
I have tried with 3 different network cards:
3com 10Mb/s
TLAN – Compaq 10/100Mb card
and REALTEK RTL8139.
Tomorrow I am picking up a new 20 euro computer 🙂