Now problems with intel3945 abg solved! I made a reg-dump from winXP and transfered corresponding values to the genmac regfile. Now xwlan 3.10 works as expected and give me connection values that is realistic. xwlan 2.13 on the other hand still give to high values. If someone else have use of the regfile I exchanged against the one delivered with genmac I will upload it here. Observe that the ssid-value is my own - I really don't know if it matters whats there as xwlan take care of this. I don't know either wich value of those I changed - which was quite a few - are really relevant. Any way now everything works spendid!
http://elfonnet.nu/gnxlnlj/netw3x32.reg