Comment 81 for bug 182716

Originally, I had the same problem - Dmesg reported that with b43 and the correct firmware installed, using network-manager to try to connect to my WPA protected network, the attempts to associate with the access point would repeatedly "time out".

Using Hardy Heron with 2.6.24-16-generic kernel.

Here's my card info:

00:0a.0 Network controller [0280]: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller [14e4:4320] (rev 03)
 Subsystem: Linksys Unknown device [1737:0013]
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
 Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
 Latency: 32
 Interrupt: pin A routed to IRQ 11
 Region 0: Memory at ea010000 (32-bit, non-prefetchable) [size=8K]

My solution was to, as has been suggested before, blacklist b43 and ssb, and modprobe bcm43xx. The steps I took are as follows:
Replaced the firmware files from a successful bcm43xx-fwcutter run that I knew from previous experience would work to /lib/firmware;
(Notice that the difference between bcm43xx and b43-fwcutters is quite important);
I blacklisted b43 and ssb, and unblacklisted bcm43xx while I was there (I used "sudo nano /etc/modprobe.d/blacklist");
Re-started, network-manager reported no wireless devices, so I just un-installed it;
Wrote my /etc/network/interfaces file by hand;
Then using ifup I brought the card up, and it works fairly okay - I not reached peak speed with it yet, but it's yet to drop packets or anything.