Well...we already know about I2C problems with the TP01 on site5.aux. I note now that Qsoil is erratic at this site and even Gsoil had a spike yesterday that wasn't seen at any other site. Tsoils are consistently okay, though. At the very least, it might be a good idea to reseat these connections in the mote box.
I also note that all Qsoils show a small spike when the TP01 is heating. The amplitude is small enough to be ignored (about 3 A/D counts), but we should be aware of this.