I just had all sort of the troubles trying to install Pharo on Ubuntu 14.04 x64.
I followed different routes and (sub)sets of instructions, but always come to either crashing or freezing.
And then, next day, everything just started to work normally.
So, I conclude, that
REBOOT is necessary at some (final) stage (which is not obvious thing in Linux world). Trouble is I don't know at which stage, and which combination of actions gives me working environment. Maybe I need to make some experimentation to make this clear, but trouble I don't know how to set my system to "fresh" condition, except of re-installing it.