Unresolved Psychotic reaction

Yesterday was the first hot day we have had since I got my Robo 3D (mid to upper 90's). I like to use my printer outdoors on the deck next to the pool (yeah, life is hard). I printed an item in PLA and things went uncharacteristically well. I knew it couldn't last. I then loaded up ABS and things went sideways. The printer heated up then began the print but first went to the bed-leveling routine. This is where it gets weird. It started the routine as usual but after the first "touch" on the front left hand side it went to the next position but instead of going down the head rose about 5mm on the z-axis. It then proceeded to the next position (now 10 mm higher than is should be) and did the same thing (now 15 mm higher) and continued in this fashion until I shut it off. I reinitialized and tried a different slicer. Same result. Could this be a "bit-flip" in the firmware caused by the high ambient temperature? By "bit-flip" I mean a negative value transposed to a positive one. That is how it is acting.

 

Thanks Geoff, why didn't I think of that?