I've spent the last two weeks looking at Memtest86+ trying to figure out if either one of my memory modules is damaged, or if it is the motherboard. These tests take a long time, and yield different results from day to day.
I've decided to never ever again buy non-ECC memory, at least not on 24/7 servers as well as on workstations.
In a gaming machine / visual typewriter? Sure, non-ECC memory is ok.