'0' for size means it's definately not uploaded right. I take it that you can still open and view the original picture no problem on your computer? If you can, I'd say maybe just try it all again from scratch as the upload might have just corrupted.
Just in case, heres how to do it. First click on the 'Delete' button next to the old one that <i>doesn't</i> work, as that picture is no good anyhow. Then click on 'Browse', and select your picture file. Then finally click on 'Upload file' and it should then get added to your web page.