Thanks for the feedback. It seems that comments can be viewed on some iPhones but not others. By coincidence, another WPtouch update was released today (4th Aug) and I have just installed it (circa 1800 BST). I also altered one or two of the settings but these should not affect the display of comments.
Please let me know via a comment below if the problem has been resolved by this latest update. If it hasn’t I will pursue the matter further.