Cloth sim; Cloth Pin and Self Collision making very bad/weird behavior? I'm trying to make pants, but these two settings I'm trying to use are causing issues with my model. 

Here is a gif of my character's pants withOUT self collision:



As you can see, the cloth simulates alright, but it doesn't self collide (as it shouldnt). The issue here however,  is the cloth pinning (the top ring of vertices at the top of the pants are pinned and parented to the character). If you look at the top area of the pants, near the crotch and waist, the pinning creates some sort of very odd pinching and rippling affect. How can I fix this?

Also, the issue with self collision:



The clothing doesn't behave properly at all, and either pinches tightly like the gif or explodes. 

Here are my settings.
I had a similar problem today. After a lot of head scratching I fixed the problem by removing doubles. I had duplicated vertices accidentally while duplicating a mesh in edit mode and the self collision was trying to separate the vertices that were on top of each other.