Thanks for the help guys. I used it this weekend and didn't see any drop in performance. After each charge the cells got closer together, even finishing on the same voltage. I have now storage charged them and they're both sitting at 3.82V.
Will keep an eye on them and see how they go. I will try charging single cells next time as well to see how each cell performs. If I have no luck, I will try a different charger.
Thanks again guys
Alex