Franco Scapin reacted overnight to a bug in MK_GPXTOOL 1.5.6 reported by Dave King. The bug was that MK_GPXTOOL could not parse GPX files created by the MK Redundant configuration. There is now a new version, 1.5.7 available for your downloading pleasure. http://wiki.mikrokopter.de/en/MKGPXTool (scroll down to below the first set of images to see the link). Thanks to Franco for such rapid customer service...and to Dave for blazing the trail into the world of MK redundancy. Andy.