Import geometry .stl

Hi,
I'm facing a problem when using geometry imported as .stl
In Ubuntu 14.04Trusty YADE 1.12, sometimes (not always) the geometry imported opens as a plane (seems to have infinite dimensions).
But using the same script in Ubuntu 12.04Precise YADE 1.07, the problem doesn't happen.
I've tried to use Ubuntu14.04 and YADE1.07, but didn't work, as well.
Any idea of what can cause this distortion?

Luis