Mega + Wishield + Ethernet

Hi. Has anybody tried to join Arduino Mega + Wishield + Ethernet shield? I am currently trying to do this. Both shields are connected right, and both work well if the other is off. I've connected Wishield SS to pin 53 and interrutpt to pin 2. Ethernet SS is on pin 10. If i turn both of them on, then only the Ethernet works. Any clue i can follow for solving this one?

Thanks