Flex shapes very slow?

Using Flex 1.0.0, I am finding that using flexSetShapes to create even a single sphere in my scene causes the frame rate to tank massively (drop from 25 to ~8 fps). The sphere is small relative to the scene and the bounding box appears to be set correctly.

Is this expected? Is there something obvious I might be doing wrong?

Thanks.

Resolved.

It was simply a bug in my code passing a bad pointer. Baffling that the only visible symptom was the slowdown…