If I remember correctly he had to resign from SuperCheats because of personal issues. I think the guy was Dutch, he was a very active member and then suddenly stopped.
What happened to Matt? He was another very active member who suddenly stopped posting. I remember him coming out as gay which couldn't have been easy for him or his parents as his older brother was also gay. He started playing Tennis, got a job, met someone he liked and then disappeared. I hope the guy found happiness, maybe one day he'll post and let us know how he is getting along.
Then there was that Darkboarder77 who hit rock bottom and found himself sleeping on a park bench because his flatmate was psychotic. His story would make a great film, he eventually met a girl and has sorted himself out.