AAARRGGHHH chipmunk pro 7.0 problem

[dugbug]

Ok I am getting closer to porting a working 6.x game over to 7.0. This one is odd. I take a rectangular UIKit view I want to bound the game physics to as such:

cpBB converter;
converter.l = bounds.origin.x;
converter.b = bounds.origin.y;
converter.r = bounds.size.width;
converter.t = bounds.size.height;

[space addBounds:converter thickness:1000.0f elasticity:1.0f friction:1000.0f
filter:CP_SHAPE_FILTER_ALL collisionType:borderType];
space.damping = 0.05f;

This worked on 6.x, but now the bounding box has no bottom. Components just fall through without colliding with the lower border. The other three sides work as expected. The size of the bounded box I am trying to create is:
x=10.000000, y=222.500000, height: 247.500000 width: 300.000000 (these sizes are on an iPhone 6)

any ideas?