I made the 2011 CustoMacMini with the i2500k i5 processor. It's been running great under 10.7.2.
I got an Atheros Airport card (Revision G) from eBay and it works natively in 10.7.2.
Gigabit Ethernet works with MultiBeast Realtek drivers under 10.7.2.
I installed Mountain Lion fresh on an empty External USB disk. Chimera on the 10.7.2 internal disk sees it during boot, when connected to a USB 2.0 port. I can choose it and boot into it without any Flags or modifiers.
But under ML, the gigabit ethernet says it's present but only grabs a fake 169.x.x.x address. It's connected directly to an Airport Extreme and should be on a 192.168.x.x network. Airport Utility can't find the base station. Again, if booted into 10.7.2, it detects the 192.168.x.x address perfectly.
The wifi won't turn on. Like it doesn't know how to power/detect the card.
I've tried trashing the "NetworkInterfaces.plist" and the "preferences.plist". Same problems on reboot.
I've tried copying and pasting the text from the working 10.7.2 files, but it doesn't work.
Do you think that the last time Apple used Atheros Wifi G cards, the software wasn't 64-bit compatible, so they dropped support for the card? If so, why would it work in Lion?
I applied the 10.8.1 update with NO PROBLEMS, but it didn't solve any of my networking problems.
My next step is to try to install the networking files from MultiBeast 4.6.1. If that doesn't work, I'll try wiping the disk and installing Mountain Lion from scratch, but I don't really see how that will help.
Any tips? Advice? Work arounds? Thank you all for your time and consideration! BL5K!