A friend of mine was having connection problems with the Broadcom 4321ag wireless card in his HP DV 9000. It would always cut out and could never connect. I found that searching google always yielded older drivers than the ones already installed. So I searched the HP website and found the latest version 5. 30.20.0 Dated August 6th 2009. For now it is working much better. I threw this post together quickly because Google didn’t have a solution, and well now it might!
Update: I have now linked this to the Revision history page, which should always display the latest version as the one I posted is clearly out of date!
You can download the drivers at this page