[CentOS] Broadcom Wifi Problem

I have a Broadcom 802.11b/g hardware on my dual-boot laptop.
Note first that in the WinXP partition, the wifi makes DHCP
connections to my router with no problem.  Since this
was not working in my new CentOS 6 partition, and
remembering that there was a driver problem with the
old Fedora partition it replaced, I followed instructions
founs at:

http://repecka.net/en/2011/04/19/install-broadcom-bcm4311-802-11bg-wlan-
drivers-on-centos/

and

http://www.broadcom.com/docs/linux_sta/README.txt

modifying for that fact that I use wlan0 rather than eth1.
The wifi is now dead-in-the-water.  The wlan light now
remains red, and neither ifconfig nor iwconfig show any
sign of wlan0 (contra to the situation before I installed
the new driver).  It still works in the WinXP partition.

Suggestions for my next step in fixing this would be most
welcome.

Thank,
Mike.