You are probably using Internet Explorer 9 or higher (if there is a higher one than 9 lol). There is an addon or something that you need to use to upload, or just use Firefox like I do.
Anyways, sounds like overwatering for sure, if you can't get it to upload in IE, post it to photobucket or some other photo upload site like obijohn said, then copy and past it to the reply to thread section, or drag and drop the photo there after you upload it to that site as another option