I have the same problem as described here: Question about ENC28J60 Ethernet shield - Interfacing - Arduino Forum
But I am now wondering, would it not be a simple fix to just put a diode towards the shield output pin? Even with a worst-case voltage drop of 0.6V it will still be way enough to register as 1, while appearing "open" when the gate holds it low?
Perhaps a 10k+ resistor to pull the shield output low too?