Read Instructions Carefully
This kext specially for Realtek RTL8169 with 0x8136 Device Id.
But also support any kind of different type of cards. but i've never tested yet. because i just used RTL8169 (embed lan card for my mobo Gigabyte GA 945-GCM S2C).
This kext works flawlessly on Mountain Lion & Lion (never tested on Lion 10.7.5,but u can force to try it too).
Content of Kext on IONetworkingFamily Plugins are :
You can download myHack http://myhack.sojugarden.com.
For more detail of device id, you can view on each info.plist content at IONetworkingFamily.kext/Contents/Plugins.
this kext also taken from lnx2mac kext too.
For installation, delete your earlier kext (IONetworkingFamily.kext in /S/L/E. and make sure to backup first on safety place)and just copy-paste both downloaded kext into /S/L/E and run "Myfix" provided by "MyHack" choose "full" option to repair permission and rebuilding your kext caches, after completed repairing kexts, reboot your machine.
Hope its work for you too..