I have the evolve xc x-type. It has 64-104mm 4 bolt pattern.
Well, I have about 1200 road and about 200 off-road kms on the crankset in 3-3 1/2 months (which is normal I guess). I never use the outer ring on the trails, and never use the inner ring on road. The trail rides were often in muddy conditions (nothing like racing or hardcore riding though), and when the ring was bent, I was actually in the mud.
I attached some pictures of the rings. Black is the outer, and the silver is the middle ring. I hammered it back to shape and it seems to be ok now. I haven't tried it yet though.