Upon installing 2.6.35-020635-generic and rebooting, my wireless network card failed. BCM4312 802.11b/g, using Broadcom STA driver.
Does "Broadcom STA driver" refer to the "wl" driver from Broadcom?
Yes, I believe so. "wl" is what shows up in the lsmod output. I'm running 9.04 on this machine, which has the driver pre-installed, but on 9.10 and after it needs to be downloaded through the hardware manager, and shows up there as "Broadcom STA". So the driver works under 2.6.32, but as I wrote, it fails to work under 2.6.35 (I haven't tried .33 or .34 yet on this machine).
Ah...well, I'm sorry. I can't support an out of stream driver. I suggest you seek support from Broadcom and/or whatever channels Ubuntu provides. Good luck!