I don't know what or why it's happened, but it seems I can only leave a comment on a blog that has its "Comment Form Placement" on full page as opposed to embedded under post! Which sounds confussing but is quite simple really, it means when you set up your blog, under settings on your dashboard you select comments and scroll down to "Comment Form Placement" and make your selection, I actually had my blog set to show comments under my posting, but have now changed it to full page, if you click on comments below this post you will see what I mean. So I appologize to those people who think I am ignoring them but can only now leave comments on blogs set up as mine is now! (its so frustrating!!)
Thanks for visiting, I do so appreciate it.