In some forums the reply form has two "Submit Reply" buttons instead of one "Submit Reply" and one "Preview".
(And even submitting this post I get two "Submit New Thread" buttons - no preview)
And the "add link" button only seems to allow me to add one link per post. I can get round that by manually entering the [url="...] etc but it's a bit of a pain in the neck. Is this a deliberate anti-linkspam feature?