Sorry to revive an old thread, but I have this issue and these resources didn't help me.
I Have a UNO with a TLC5940nt and the ethernet shield.
When I follow the wiring and software changes listed here, neither the tlc, or ethernet shield work. Furthermore, If i make a connection between pin 10 on the arduino and pin 10 on the shield, the shield will respond to pings, but nothing more.
I've confirmed numerous times that they both work independently of each other, just not together.
Any ideas?