[svxxx26]

<<.how come when I click on one icon, it goes at the end of the message, and when I click on another, it goes in the heading?>>

If I understand the question (which in itself would be a great leap), here is the explanation:

When you click on the TOPIC or TITLE of a particular thread, you will be taken to the first message of that thread.
If you click on the NAME of the last person to post on a thread, you will be taken to that persons post.