I have Mint on two different laptops, and I have two different routers. One uses WPA, and the other WEP (it doesn't have WPA as an option and was issued by the ISP). One laptop has an Intel wireless card and connects to both routers without issue.
The second router has a Broadcom card and will *only* connect to the WPA connection. When I try to connect to the network, it doesn't even ask me to enter the passcode- it just immediately says that the connection failed and I've been disconnected.