In that same thread there is a link to this post on another thread:
http://forum.mikrotik.com/t/wireless-wire-cube-preconfigured-plug-n-play-doesnt/173973/1
Where the standard configurations of a pair ( both master and slave) are posted.
Since you already have one half of the old (good) configuration, It should be easy to recreate the other half with those bases.
From what you report (working but much slower speed) It could be possible that they are using the (backup) 5GHz connection instead of the primary 60GHz one.