Hi unalcalde,
on Ubuntu you could install qelectrotech-dbgsym_0.51.r* package in my PPA (debug package).
https://wiki.debian.org/HowToGetABacktrace
We know two little bug which can crash QET :
In diagram, selecting with mouse a area which contain elements, conductors, and basic shapes and delete selection can provoke artifacts, and crash if you want to save or refresh view, without corrupt project.
In editor element : random crashes but we don't know how to reproduce it exactly.
"Le jour où tu découvres le Libre, tu sais que tu ne pourras jamais plus revenir en arrière..."