[ODE] building a tower

[Yann]

I tried to simutate a tower of bricks rammed by falling stones.

But when performing this idea many internal errors occur.
The bricks slide into each other and after a minute or so the tower 
collapses!

Do I have to disable the tower bricks to have a well running simulation?
(I saw and example in the internet, where several balls rolled into each 
other, I looked at the source code and realized, that the engine does 
not disable them. It runs properly although!)

(grep finds dGeomDisable()'s header in the header files, but I miss the 
function body, and when compiling I get an undefined reference to 
dGeomDisable)

thank's
Yann