John - Don't feel bad for having difficulty posting photographs. I have some of the same problems which is why I do not post pictures. I don't need those type of difficulty and problems. So I have given up trying.
What Bill said, I can jump thru hoops and downsize it to get a photo to post but it seems to be a pita, so for the most part I dont take the time, and maybe that is the results they are looking for so as to not clutter the forum up with too many pictures.
It definitely wont load straight from an iphone and I think the reason for that, or at least what I have found, an iphone takes hi resolution pics that are way over 2 megabytes. unless you have a way of down sizing them, thru emailing them to yourself via a screenshot and then saving, dragging, or otherwise attach them to a post, they will be too big to post.
