Mustis was fired over "songwriting credits" which just sounds like a bullshit reason to me.
However, Vortex was fired for being a drunken moron. He forgot his bass at a festival in Europe, and was so drunk on stage that he could hardly play a lot of times. I remember seeing them a few years ago and after the performance, I got my ticket signed by most of the band, and I came over to Vortex. He was being held up by about 4 girls because he couldn't stand of his own power, and he told me this in a super thick Norwegian accent:
"I come to America because of your women"
It was rather funny, but you could tell the guy had problems with his liquor.
I received...an "advance" copy of the CD if you will...it isn't their best work by far but it is nowhere near as bad as Death Cult Armageddon, which I believe to be their worst album. This album probably is in the middle.
I did enjoy In Sorte Diaboli as well. Pretty solid album. My favorites are still Enthrone Darkness Triumphant, and For All Tid.