I am using nightly build, August 17.
After taking a picture, the bottom left corner of the LCD states, "Deflickering..." until image review stops. If I leave image review on "Hold" via the Canon menu, then the deflicker message just stays onscreen until I cancel out. I didn't find this interesting until I plugged in my SD card to my PC. No sidecar files. I have tried both XMP and UFRaw. If there is some sort of log I can attach, let me know and I'll happily do it.