Well, tried all options and got nowhere. One option appears to have worked though, unchecking the Opera Icons and going to 'Include' and selecting the Opera icons folder. Now works no problem. I am still a bit concern for why the original way will not work and whether I have some sort of Trojan hanging onto it?!?
Anyways, cleaning the custom folder does appear to be working, THANK YOU!!
I have also disabled Opera from using the favicons as suggested earlier. I will try and experiment to see what I can get on. I need them really as I have no text for my bookmarks!
..a short time later..
Interesting, I can now allow favicons and it all works. If I clean through the custom method first and then untick custom and tick the opera website icons, that also works (the file though is obviously empty). If I go Opera website icons first, it just crashes. At least its working.