Give it another whirl and see what happens...One thing I didn't know that might help is when I went to where u directed me it said click on upload file. Which I do. Then it said I can choose either thumbnail or full size. But when I click on upload file I never get that choice. I just choose pic and it fails. Got the size under 1mb as well. Now I have posted pics on here before. Sometimes it works sometimes it doesnt.
(are you using a PC or handheld device?)