Wow... lots of info here.
I finally got me a ET-73 some time back. I had nothing but problems with it. Finally go ahold of CS. It is straight now. I am using it right now for a pork butt.
One thing I did notice on the messages is that some say the probes on some thermometers go belly up after a few times of use. I too have "lost" a couple of probes going bad..... I found out that if you run the wires out and close the lid on it, it can pinch and damage the wires. They are very small in diameter, and can not take too much abuse like that. Also, if there is a temp spike, sometimes it can cause them to loose a connection.
I now wrap them in heavy duty foil lengthwise. That helps insulate the wires, and also cushions them against the lid some. Just use care, and they will last a long time.
Bill