Agreed. Full-back is a big problem for us. But not only has O'Shea done well in the CB pairing with Dunne, he has been COMPLETELY TOILET at full-back whenever played there in the past. I don't think i'd actually seen him have anywhere near a good game until this campaign.
I cannot understand these suggestions that O'Shea be moved back to LB. There would be limited improvement at LB, if any, and it would break up what has so far proved to be a decent CB set-up.