I've received the RX today, it feels really good on my hand and it looks quite new. Too exciting i mount my CZ 50/1.4 onto it and pressed the shutter button, guess what. The mirror was stucked. I turned off the camera but the mirror did not go back down. I had to take of the lens to release the mirror back to it's position. It has this problems with all of my MM lenses but when i tried my 85/2.8 AE, then it goes fine.
What is this problem? My lenses or the camera? Do you have the same problems with other Contax, say, ST, RTS... ?

If I remember right there is a small mirror swing arm in the mount, if the camera has not been used for a while it can cause the problems you mention: locate the little arm and give it a little exercise. Lift up the mirror and check if it sticks, if so you need to jog the little thingy.

If that does not help:
Check the mirror and make sure nothing is out of whack and that the matte screen is firmly attached and not askew.

Check that the aperture is not stuck in the lens, try and jog it a little.

I have had the RX and there were no problems ever with mounting lenses, MM or not, but I have seen the problem you mentioned on other cameras, albeit not Contax.

Great camera, the best I ever had, hope you get it to work properly.

regards, Henrik

Thanks for your quick input. However, to the best of my knowledge, It seems the mirror crashs into the end of the lens. I've tried to move the mirror but it goes OK without lens mounted onto camera. There is no sign of stickness whatsoever. This camera works OK with all my AE version.

vaguely I think that some of these cameras had glue problem with the mirror and it would 'slip' in the metal holder. This also throws focus off.

you2 wrote:
vaguely I think that some of these cameras had glue problem with the mirror and it would 'slip' in the metal holder. This also throws focus off.

This is exactly the problem. The glue on these cameras is quite soft, and it isn't unusual for the mirror to slowly slip over the years and protrude from its frame, especially in hot climates.