Check your installe dprograms against this link and the ones listed there from 3.4f.viewtopic.php?f=52&t=10046&p=60486&hilit=ipw2200#p60486
There is 2 knetworkmanagers , the listed programs there is working currently for ipw3945 / bcm43xx / ipw2200 Maybe this would get yours to work as well.
If yours is the same then it could be something else and then it is easier to find the problem.
Dhcp 3.0.8 or there abouts was buggy so before 3.0.6 or after 3.0.10 should work.
Usually the 28% is about where authentication happens or 80% is dhcp not sure just guessing about this.