I have recently got a cheap laptop and it has a relativity new Broadcom WIFI device; it does work with the native driver in the 2.6.24-rcXX with a patch. But as this new driver is based upon mac80211 I was bashing my head for a couple of days regarding how to inject packets.
Simply use the development branch of aireplay-ng for success.
svn co http://trac.aircrack-ng.org/browser/branch/1.0-dev/
cd 1.o-dev
make
sudo make install
Happy cracking!
DanB UK.