Hi, I am running vl 5.8 and one mistake I made was using the ndiswrapper as the driver like this
wpa_supplicant -B -Dndiswrapper -iwlan0 -c /etc/wpa_supplicant.conf
I went to the ndiswrapper at sourceforge http://ndiswrapper.sourceforge.net/joomla/index.php?/component/option,com_openwiki/Itemid,33/id,wpa/
and found you should call it with the wext driver like this
wpa_supplicant -B -Dwext -iwlan0 -c /etc/wpa_supplicant.conf
wext will figure out the device is supported with ndiswrapper and call it under the covers. Once I made this change it worked fine for me.
one other issue, I had to try several different winxx drivers before I could get connected, so you may need to experiment a bit.
I hope this helps.