Assuming all the page elements have loaded and you're viewing a topic with sufficient posts to cause your browser window to scroll vertically then there is nothing I can see that goes against conventional browser behaviour. i.e. Internet Explorer and every other browser should behave the same and "jump" your viewport (the bit of the webpage visible in your browser window) to the new post where the new post ought to appear towards or at the top of said viewport.
I'm confused if your not seeing this behaviour
Do you have another browser to try just for the sake of eliminating IE from the equation?