I made a beer can chicken in the One Touch last night.  It turned out nice, but for temperature reading I dropped my probe down the top vent, and put an oven thermometer on the grill.  The grill thermometer read 25 degrees less than the probe.  I figured 325 or 350 was fine for the chicken, but I'm wondering which thermometer is more trustworthy.  Should I get a new oven thermometer?  Should I use the probe only for inside the meat?  I did eventually move the probe inside the breast and took it off at 165, and it seemed accurate for that.