damn it !
I am out of ideas...
Except, of course, to find a usb stick that is compatible, loads around, do a search... but of course its not ideal, but at least temporarily.
You could try with another pcie card, broadcom or atheros.
Your card should be working fine !!! I know how irritating this can be, hang in there.
Another thought. Where did you put that kext? S/L/E or E/L/E ?
IF you used OSXtools, or manually, do the following.
Copy the kext out of S/L/E to desktop, then delete the kext from folder. Copy it to Extra/Library/Extensions.
Delete extensions.mkext from S/L
Go to disk utility and repair permissions.
Reboot with -v -f
-f is the same as deleting extensions.mkext, but on boot it forces deletion again and rebuilds.
Just for reference, I have mine in S/L/E, but for some reason you might need it overriden. Could be something to do with a not so friendly dsdt.aml code...