Fedora Networking :: Cannot Get BCM4312 Wireless Card Working

I recently purchased an Acer eMachines E525 laptop, and currently have it dual booting Windows 7 and Fedora 12 x86_64 with the 2.6.31.5-127 kernel. I've been completely unable to get the wireless card working in Fedora (it works fine in windows).

lspci lists the following about the wireless card:
Code:
Network controller: Broadcom Corporation BCM4312 802.11b/g (rev 01)
so I assume it's a BCM4312.

So far I have tried downloading the driver from [URL] and then trying to install it according to the accompanying readme file: [URL]. However, when I try to make the driver, I get the following message:

Code:
KBUILD_NOPEDANTIC=1 make -C /lib/modules/`uname -r`/build M=`pwd`
make: *** /lib/modules/2.6.32.10-90.fc12.x86_64/build: No such file or directory. Stop.
The Readme says that if I get this kind of error, I need to install the "kernel-devel" package, but I have this installed and it still returns the same error.

I have also tried following the fw-cutter instructions for fedora from [URL], but it still doesn't work. I realise there's the option of using ndiswrapper, but I gave that a shot with Fedora 11 on the same machine and had no luck, and I'd really like to see whether any of the other options work before going down that route.