As was noted by Sorunome and I am sure others, BatLib's introduction of GroupHook caused a mysterious bug with graphing. It seemed to cause undesired shading of graphs causing some interesting effects. After chasing through the code, I found that it was caused by copying the GroupHook code to the end of TempSwapArea. I had never seen documentation of this anywhere, so as I experiment further, I hope I can provide the information. Until then, i need to find some other 65 byte chunk of free ram that I'm not already using.

I use that link quite a bit, actually. Also, it seems that almost all of TempSwapArea is used during the graphing process.
EDIT: The weird part is that a lot of the data is clearly FP values, not code from flash as it is normally used for.