My first ZI quickly developed sticky frame lines: I think it was the 35mm frame that wouldn't go away under certain circumstances (2½ years ago...I don't remember exactly). Returned to dealer, and as he predicted, Zeiss sent out a new one. A month or two later in Xi'an, China, I'm shooting some slide film, and the light meter goes weird on me. Fluctuating readings... what the?? I look at the shutter speed dial, try to move it, and find that it's now free wheeling; it just spins around apparently unattached to anything. I had brought my M4-2 along for b/w, but it then became my only camera. On my return to Toronto, I returned the ZI for a refund, as I'd lost confidence in it.
I treat my camera gear carefully; it stays in a bag until I want it, then it goes back in the bag. I don't shoot street, and I'm slow. I don't go on group shoots because I'd drive everyone crazy. My point here is that the camera failed on its own; there was no abuse.
Having said all this, I'd almost like to get another one as I really liked the camera. However, I'll stand pat with my meterless Leicas and throw spare loonies and twonies into an M9 jar. Some day maybe.
I was surprised that anerjee had the same loose shutter speed dial problem. Is that chronic? Zeiss?
The serial #s on my ZIs were 155921** and 155923**.