well if you're uploading straight to stangnet there is some limit which might be your problem, and when you are uploading straight to stangnet it take a whole lot of time so you have to be patient even when it appears not to be doing anything. If you don't have dsl or better you probably shouldn't even try.
what i do is host my pics on cardomain.com, open the page (with internet explorer) which the picture is displayed to the public, right click, hit properties, copy the address, come back here, hit the image button and paste.