And to think that's I've been settling for less betta all this time :-D
Derek... There is no way that chicken at 175 degrees is rubbery and raw. Either you're thermometer is way off, or you are measuring in the wrong place, or you are not using a thermometer designed for measuring meat temperatures. Something is not right.
We've been through this before. Check you're thermometer in boiling water to get 212 (or something close, a degree or two is good enough) then check it in ice water to get 32.
When you test the chicken, put the thermometer into the meatiest part, near, but not touching, the bone, and try to get th tip of the thermometer (where the sensor is) in the middle of the meat vertically. If you go in too far the tip could be too close to the outside of the chicken on the bottom, or even poking through, and giving you a false reading.
Also, what type of thermometer is it? A thermometer designed for use in an oven or a deep fryer may not read properly when stuck into a piece of meat.
If you're serious about cooking competitions I would suggest buying a good thermometer. A bunch of us swear by the Thermapen, but you don't have to spend that kind of money right away. The same company (Thermoworks) makes a couple of lower priced thermometers that are fast and accurate. Take a look at these...
http://www.thermoworks.com/products/low_cost/rt600c.html
or
http://www.thermoworks.com/products/low_cost/rt301wa.html