Kernel compiled and installed, including b43 module. Firmware cut and installed. Haversack rebooted into new kernel version successfully.
Wireless finds my AP, connects, negotiates, gets an IP and configuration from DHCP successfully. It works for approximately two seconds and then stops working.
But it seems like it will still work if the ethernet is also up and plugged in and connected.
I'm confused and frustrated. Have requested help in IRC.