[ODE] gravity issues

[Tiago Rodrigues]

Hi,
I'm doing some testing with various physics sdks.
I'm trying to check whats the behaviour of each one with the same 
examples, with real values, meaning real gravity and sizes.
For example i set gravity to -9.81 (m/s/s), and create a box stack each 
with 0.2 (m) side and 0.1 density, with  5 boxes.
I can't get a stable stack, the boxes simply start to penetrate each 
other and the stack desmantles.
If i lower the gravity to values as the ones found in the examples 
(-0.5) everything works fine.
What can i do to make the simulation work properly in the presence of 
real gravity?

thanks in avance,
Tiago.