Softbody Troubles

For some reason, whenever I try to make softbody clothing in blender, 
it always falls through the mesh, but only on the right side.  I've 
checked all of the dampening, collision, ect settings, and they all 
end up giving the same result.

It may or may not be relevent, but I always model the left side of 
people (the side the softbody works on), then duplicate it to form the 
other side.  I'm not too experienced with blender, so I don't know if 
that might have an effect.

Any advice would be helpful.