On U <-> Mikey Dread

Found these On U riddims on Mikey Dread songs:
African Blood/African Dub (Congo Ashanti Roy / Singers & Players) -> Childhood Days (Mikey Dread)
Breaking Down The Pressure (Congo Ashanti Roy / Singers & Players) -> Autobiography (Mikey Dread)

Update: Of course I'm hardly the first to catch this. David of Skysaw.org documents and explains here http://www.skysaw.org/onu/artists/singersandplayers.html