Interesting, its not just me.
I started with V4 esprit which only worked properly after I reinstalled Windows (every once in a while).
Currently I have V5I which I got free with Lightwave, definetly an improvment stability wise.
Couldnt bring myself to get V6I looked to much like a service pack.
V7 looks sweet but the convertion rate of the Aussi dollar makes a purchase looking unlikly.