[ODE] Vector has zero size

[join at krakendev.com]

I find I am frequently getting the messages:
ODE Message 2: vector has zero size (ode/src/odemath.cpp:120)
and
ODE Message 3: LCP internal error, s <= 0 (s=0.0000e+000)

As I understand it, message 3 is telling me that the system is becoming
unstable, and that I should be able to improve this with doubles and some
fine tuning.

As for message 2, is that saying that some vector has 0 magnitude or that
it is somehow invalid?

I'm receiving these messages after setting some desired joint velocities
to "sort of" random values in the range of -10 to 10.