Ok, there was also an applicable line in the /etc/wlan/wlancfg-mynetworkname file.
It said AuthType="opensystem"
I removed the quotes, and now iwconfig shows that there is an opensystem
However, udhcpd still does not connect.
I noticed that in iwconfig's output the bit
IEEE 802.11-DS
however, in my working laptop interface it specs
IEEE 802.11g
does this make a difference ?