[ODE] Stacking objects

[Jeffrey Smith]

> > How can I reduce this error? 
> 
> http://opende.sourceforge.net/ode-0.035-userguide.html#ref88

Alas, I've tried all these simple techniques (those that are
applicable anyway) without success.

> > Would fixing ODE to use doubles instead of floats for dReals
> > affect this?
>
> Depends on where your error is 'coming from' (numerical
> error vs contradictory constraints, etc), but double doesn't hurt.

Is there some general way I could detect contradictory constraints
(prior to solving the LCP, preferably)?  I'd planned to fix ODE to 
work with double dReals already, so maybe I should do that sooner
rather than later.

I've been able to increase stability greatly by using the "old way"
(directly factoring and solving) of solving the LCP, rather than using
dSolveLCP.  Unfortunately, this appears to mess with surface bounce
(in addition to being slower) so it's not optimal.

-Jeff