This forum is for scupdates and you should post any NetChk product questions in the Shavlik General forum.
Apple silently released 188.8.131.52 one day after they released 184.108.40.206. After digging on their support forums, they introduced a bug that broke Apple Sync. 220.127.116.11 fixed this issue. You probably haven't heard about 18.104.22.168 because they did not announce this product.