Noisy Thermocouple?

Can anyone take a look at this live cook and tell me what's going on with my thermocouple? It'll read what I believe to be normal for 3 or 4 seconds then drop about 3ºF, and continue with that pattern.

http://ficklin.afraid.org:5000

DId you do the SMD soldering yourself or buy a pre-populated board?
There isn't much between the TC amp and the ATmega, just the 100K resistor (that is standing up behind the TC jack) and the cap next to it. You might try reflowing solder on that and the corner pin of the ATMega that is near there. You could try turning on the AC Input Noise filter in the HM config, and could also try a different 12V power supply. You definitely have a lot of noise on your TC input (as indicated by the red squiggly line) so the noise is what is causing the TC temp to fluctuate.
I am also wondering what kind of TC you have? Some are grounded, others isolated, the grounded type seem to be more prone to noise problems. I always run isolated TC's, even with my external RDTC board and ~50ft of CAT5 cable between it and my HM I get zero noise and rock steady TC readings. (using a Thermoworks TC)

Turning on the 60Hz noise filter would be the first thing I'd try.

I second Steve_M's recommendation on the A/C input line noise filter as a first item to try. Then try a different thermocouple.

Do I need to be running a different firmware for the noise setting?

- - - Updated - - -

Also, this is the first time it's ever showed this behavior.

So, what do I need to do if I don't see the "A/C Input line noise filter" box?

Upgrade the OpenWrt and AVR code to the snapshot version.

See here: http://tvwbb.com/showthread.php?63388-How-to-Upgrade-HM-software

That did it. Maybe the next cook will go "smoother".