Let me back up and explain why I was asking about monitoring temp drift over time. I noticed drift when using the DSO with standard or alternative firmware when measuring RMS. This is about the same time I lost access to pawn. There is several volts drift after minutes.
I just checked the volt meter readout with pawn and it is rock steady. I also checked the Vref on the ADC.
Now I assume there is a bug in the RMS calculations.