I did remove the GenericUSB kext
So, here's my results, after performing the commands you requested:
beastie:~ mm2margaret$ ls -l /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/ | grep E1000drwxr-xr-x 3 root wheel 102 Nov 6 16:28 AppleIntelE1000e.kextAnd:beastie:~ mm2margaret$ sudo touch /System/Library/Extensionsbeastie:~ mm2margaret$ sudo kextcache -u /(meaning no errors, I think, because it didn't kick out anything....)And, sadly, still no luck.....still getting a 169.254 address, and even a valid manual ip address assigned, I cannot ping it's default gateway, while the realtek can (if it's plugged in via an ethernet jack).
That is ok, one thing at a time.
Although your card was loaded, I wouldn't be surprised of weird behavior by the OS given the problems with permissions or cache. Granted, you could be booting without caches already, but it doesn't hurt to be sure.
I'm assuming you can still find your card being loaded properly and everything.
Next step you could try is to reset your network interface settings, by moving the config file out of the system configuration folder and then restarting:
mv /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist ~/Desktop
Try that, see if it helps.