Wireless networking degraded with Fedora 18

[Miner, Jonathan W (US SSA)]

I have an HP laptop with an integrated Broadcom controller:

02:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN
Controller (rev 01)

I recently upgraded to Fedora 18, and have noticed a big difference between wireless
networking performance.  With Fedora 18 running, and sitting about 10 feet from a Linksys
WAP54G access point I get "one bar" on the Gnome icon... if I double the
distance, I start losing the connection.

If I reboot to Fedora 17, I get three/four bars at 10feet, etc.

I've checked the internal antenna cables, and made sure that each OS is running the
most up to date kernels.  I even used a spectrum analyzer to look for noise in the 2.4GHz
spectrum. I don't have any external USB WiFi adapters to test with.

Any ideas?