Tom,
Check your comms quality from WeatherCat's status window (Tools->Status) - it should be pretty much 100%. If not check the comms and sensor errors - comms errors are errors are errors related to the local connection between computer and console , sensor errors are sensor reading outside manufacturers stated range or just plain missing. Comms errors normally indicate either some USB driver or USB cabling issue, sensor errors are normally related to either low batteries, wiring issues (if wired) or RF interference if wireless (more info in the WeatherCat manual). The Live Data View will break out sensor errors by sensor and will give a good idea of which sensor is not being received correctly.