Yeah, Dom, I read a lot on it. Apparently he'd travel back to Oslo *during* tour, many times, just to do something with the church or his own personal religious things. Nothing wrong with having a religious affiliation, of course, but it doesn't seem like that's something convenient to do while on tour! Thomas certainly wasn't happy with it, but I guess Roy's had some sort of revelation/'rebirth' and is following his own path now. Apparently that's why they postponed the 2010 North American tour for a year, because Roy was falling ill - physically or mentally, or both, from the reports I've read.
Needless to say Thomas certainly wasn't pleased for a while after he announced his departure and he came off as such in interviews...