I have recently bought a DELL 510m.
Unfortunately, the on-board chipset for the wireless card is a Broadcom
Vendeur: Broadcom Corp.
Description: BCM94306 802.11g NIC
For which not Linux compatible driver is available. A solution, as suggested herebefore, is to install ndiswrapper (for instance) and use the Windows drivers under Linux.
The only constraints are:
1) install the source code of your current kernel;
2) retrieve the source code of ndiswrapper (sourceforge.net)
3) compile this last code
and follow the installation guide.
After a few attempts, it should work ok.