I just received notification by Microchip that they've released an Errata Datasheet for the PIC18F8722 Rev A1 wafer. It outlines a lot of the known problems with the die (and some workarounds, if discovered). (FYI all: The PIC18F8722 is the 2006 Robot Controller's CPU.)
"PIC18F6627/6722/8627/8722 Rev. A1 Silicon Errata"
http://ww1.microchip.com/downloads/en/DeviceDoc/80221c.pdf
Every team's Programming Group should probably download this to their CPU doc area and review it, so you're all aware of the software vagrancies of this die. It may strongly assist you in debugging code, when things don't seem to work as "advertised".
I hope this helps!
- Keith