Ok I understand.
It shows as a url right, did you click on the Preview Post button ( it's right next to the Submit Reply button ) to see how your post would look? It should work.
When your typing a message just the url addresses will show, no pictures, click on preview post and if you still have urls showing then yes something is wrong.
When you copy the url from photobucket and use the little yellow thing above remember to remove the html tags with < and >
The url will look like this:
Code:
[img]http://www.photobucket.com/YourImage.jpg[/img]
Or just replace each < with [ and each > with ]
Let me know if you get it working or not. It's quite easy when you understand how to post the url with the right brackets ( [ and ] ) not (< and > )