Hi,
I have solved my issues.
This post: http://forum.mikrotik.com/t/default-route-from-bgp-to-ospf/88625/1 sorted it out.
Few things:
1: I had routing loops due to default route problems in ibgp, moving default routing to ospf sorted it.
2: Then I ran in to the issue where Mikrotik will not bring the default route from EBGP to OSPF (version 6.42.6) and seems to be a known issue, but nearly 1 year later is still there.
3: I made my problem worse by have route reflect marked on the peer between the Route Reflectors as well. My Bad.
All in all a very useful thread by people who know what there doing. Thanks to all.
Alex