I've seen this, and I can reproduce it on demnad too. To fix, I had to select Center Forms on Page in the Publishing properties, then in the form I selected Auto Component Order and Auto Tab Order.
What I've found is on a form the first item that we generally add is the Submit button. This gets the component order and tab order of 0 or 1 (depending on wether you have any othe items on the page). I thinkt the syste is trying to show the fist tabbed or ordered item, thus it's scrolling down so you can see the button.
Rob