I only purchased my Z600 on Wednesday but have been absolutely delighted
with its performance ...until about 2 hours ago that is. My phone rang but
when I picked up the line was totally dead. I rang back the caller and again
the line was dead with no ring tone. I recalled him on my desk phone and he
told me that when he called me initially the line went dead at his end when
I picked up and when I called him back his phone rang but he had a dead line
on pick-up. I called my wife's GSM and my desk phone from the Z600 to find
the same result, dead line with no ring tone.
I turned the phone off and then on to find that the problem had
"disappeared".

Is this a known issue or is it just a one-off?

Phil