Quick update. I got a call on Monday from the same guy. He's sent on my samples (and some other ones) to the Sony team of experts (so I'm told) in Brussels for analysis.
Another sample that was sent on:
With the bank holiday coming up I'm not expecting anything to be resolved, but...at least I have the camera and it can be used for "normal shooting" this problem only seems to happen in extreme contrast situations. I am starting to think that there are only a couple of logical explanations. I've checked the serial numbers from both bodies and this new one has quite a spread number wise so it's clearly a later production A57 (sometimes stock can be a bit older than expected my Km5d was bought very late in production, but had the FBF issue)
I can only come to a few conclusions:
1: This could be a model problem (ie something that can effect all A57's)
2: It could be a production issue that causes the problem and has hit various batches of this model
3: It seems quite unlikely that it's just a few iffy bodies out there, statistically quite unlikely I would get 2 iffy ones in a row (and one failed repair one too)
This green line problem could be an issue for interior shooting, whilst I don't do a lot I have seen some green (quite mild and feint though) in some shots.
Whilst I've had a grab of a few SLT models in the past, I can't comment regarding this problem as I was not looking for it.
I have at this time no idea if A65's, A77's or even A99's (or any other models even older ones) might have a similar problem
I would ask any SLT users to check to see if this happens to them green line or not.
So far I have not managed to find any other discussions or mention of this problem on Sony Alpha products!
I will see what he says when he gets back to me, ie what their solution is.