Hello, I was doing an internet search for the problem my Contax TVS developed, and I found your problem to be very similar to mine. Actually I've narrowd down to an autofocus issue, whenever the AF kicks in the camera turns off, and only by retracting the lens to the OFF position the shutter is activated and the film advances. At first it was more frequent with higher focal lenght (aprox. above 40mm) but now it happens even with the lens at its widest.
Have you found a solution yet? I live in Mexico, and the chances of getting it repaired here are very slim... and with the money it would cost me to send it to the US I can almost buy another used one. So, I really don't know what to do, I think it's an excelent camera to let die, yet I am somehow limited by budget.
Thank you very much for your time (: