Hi sqldba725 and david.bianco

thank you both for your replies. I have fixed the problem... well I will say so far so good.

One of the possible cause I found on the internet was windows update KB2840628, the only problem was I did not have it installed.

Anyway to cut a long story short, I cloned the VM's involved and ran ALL the Windows updates to do with .Net Framework... tested and replication now works. I will spend some time of the next couple of days testing/reviewing before changing the actual production VM's. "fingers crossed"

Thanks for the replies greatly appreciated.