Comment 9 for bug 81812

I also have trouble using a 'D-Link DWL-G520+' card with 'feisty'. The kernel spawns messages like the following over and over again:

  '[ 387.488260] wlan0: association FAILED: peer sent Status Code 18 (Assoc denied
   : requesting STA doesnt support all data rates in basic set)'

However, there is an easy fix to this which is to set the transfer rate manually to a value supported by the access point instead of using the default 'auto' mode. The access point I am using only offers 'Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s' which was the cause.
After setting the rate to 11Mb/s, everything worked like a charm.