I had the same ghosting issue. Upgrading the base software alone does not get rid of it. You have to upgrade the transponder too.
Scott- 2018 dues paid
Got medical back, now building a 7A.
RV-12 #120515, 319RV over 220 hours.
1st flight 12/08/15, flew SNF, Oshkosh, Triple Tree & SERFI in year 1!
RV-9A, 536 hours, sold, RV-7 sold, Kitfox sold