You are the first I have heard of any EP600 issues. That said, I'm sorry you are experiencing issues.
However, rest assured Axiom will make it right. I would definitely take the upgrade offer on the EP800 and move on to deep wall shaking bliss!
M80's, QS8's, M22's, CHT SHO-10, Dual CHT SS-18.1's, Onkyo NR3008, Mitsubishi WD-73740