I have been playing with the mooshimeter a bit more.
With no leads connected to the meter, set both channels to INT.
Now set one channel to resistance, it will show OVERLOAD. Then switch back to INT and temperature reading will be ~0.6C higher than the other channel.
Now set one channel to Aux Voltage DC. It may show OVERLOAD, wait till you get readings and then switch back to INT, temperature will read normal.
Now set one channel to Aux Voltage AC. Readings show 0.0000 or 0x000000, then switch back to INT and readings will be -271.5C or 0x000000.
Also when in Aux Voltage DC the readings seem to float, short the leads together and then opening them again. Now when you switch that channel to INT, you get OVERLOAD.
All this applies to either channel.