I might as well quote something from HTML Goodies (out of the top of my head):

Close every single tag, regardless what the type is. Only the following tags don't need to be closed:

<br> <p> <hr>



Which means you still have to close the <a name="jump"> tag with </a>
I always do that, and it has worked perfectly. I suggest you to do that too. That way you'll be 100% sure the tag is working properly.