Rejoicing was a bit too early.
It turns out now that apparently the problem is that connection can
only be established when the HP 2133 is very near the router. If I connect
that way and move away the green bar at the WICD applet turns yellow
and it says connected to linksys at 20% and there is no more data flow.
Before the MoBo change the HP 2133 could be used all over the house.
The fact that I got a connection at the PC shop must be that the router there
is near by.
My neighbour with his laptop has no problem with my router everywhere
around the house like with the HP 2133 before.
When I got finally the connection yesterday I was in front of my PC where the
router is as well and followed the instructions given right there on the HP 2133.
If I would have been sitting farer away I would still report: Can't Connect.
So we can make a connection, however, only close to the router.