OK found out what was wrong - in the past I had loaded packs from another supplier, actually two other suppliers - no names to protect the innocent. It's these that were making the display such a mess. As they were not usable, just deleted all other manufactures products and just left the Platinum ones.
All seems much better - still the odd strange display but basically each library is now together and displays much more like (probably the same) as the AD stuff.
HOWEVER the Addictive Drums browser is STILL the one of the worst for displaying midi loops coherently - a couple years ago, BDF Eco was on sale for $15 I think, so I got it. But I have never used it much as the browser is rubbish. Studio Drummer came with Komplete - again not used that much - that's sounds also, but the browser could be better.
In my opinion the best browser is without any doubt Toontrack, followed by Slate in the packages I have - and being human, we normally reach first for the easy option.
I did write and try and explain this to the guys at XLN audio, but I really don't think they realize how a poor browser like theirs reflects badly on an otherwise excellent product.
Nigel