Probably because networking is not started automatically in BT4... I'm sure your card works, you just have to bring it up either manually or via init.d. Some caveats can be found here:also BT4 appears to missing some drivers or something becuase it diddnt reconige my old ipw2100 wifi card. (thats on the toshiba.) all it saw was local loopback.
http://backtrack4.blogspot.com/2009/...o-release.html
--windexh8er



