[ODE] Small stepsize causing assertion

[Kyle Hubert]

I wanted to reduce my step size down to 1ms, but I encountered this:

ODE INTERNAL ERROR 1: assertion "*iret != i0" failed in cullPoints() [box.cpp]
Aborted (core dumped)

If I make the step size 3ms it's OK. Is there something I'm doing
wrong? I'm using the release 0.7 built with no changes to configure,
so the defaults.

-Kyle