I am using the following temperature controller:
http://www.lightobject.com/support/TempController.htm
I purchased it on Ebay a year ago. Below is the link:
http://cgi.ebay.com/Celsius-999C-Dig...QQcmdZViewItem
The main thing is to make sure the temperature controller is set-up for the correct thermocouple. If it is not correct, your readings won't be correct. That sounds like the case with Ron's situation. One way to verify the controller and thermo-couple is to test the stystem for the correct 32F (0C) using an ice slurry, and then 212F (100C) using boiling water. There are formulas to verify at what temperature your water will boil at based on the atmospheric pressure, but that is only needed if you are actually calibrating you system. But, if your water boils and your temperature reading is somewhere around 212F, your thermocouple is probably correct.
Hope this helps.
Joel