You're oh-so close.
There are two sets of "http://", there should only be one.
Between the tags, (enclosed with brackets), there needs to be a title. I just added the text "linky".
With those fixes, what you see when entering the post is:
Which will look like this in the post:linky
Otherwise, try doing this instead of clicking on the icon for inserting a web link:
1. Highlight the URL in a browser and copy it (control-c)
2. Manually type [url]
3. Paste the URL (control-v)
4. Manually type the [/url]
5. Then click on the "Preview Post" button. It should look like this:http://www.advrider.com/forums/showthread.php?t=799080&highlight=satellite+radio&page=3