I can't tell for sure what is wrong with your post. It appears that the URL you used was to a page that contained a picture; it was definitely not a URL directly to the picture.
Here is a simple way to post pictures, if you are using Photobucket.com and the picture is no more than 640 pixels wide, all you have to do is click on the bottom URL from the 4 under the thumbnail, (just clicking will copy the URL) and paste it in your post.
If the picture is greater that 640 pixels wide, you can insert a space and width=640 after the .jpg or .gif as in the example below
Don't quote this post to reply. Doing so will cause what looks like brackets in the example above to actually become brackets. Your quote will display a distorted blow-up of the above picture and not the example.