CSS compatibility can be pretty touchy and without a link to actually see what you're doing, it's pretty hard to give any concrete answer. You also need to clarify whether by "in the same place" you mean, for example, that it stays in the top-right corner and stays there even when you scroll, or stays in the position, and moves out of sight when the page is scrolled.

As it is, try
position:fixed;
_position:absolute;

Firefox should read position: fixed, while Internet Explorer reads position: absolute

What it at least sounds like is that you want position: fixed in both Firefox and IE. Try this link, and start with Firefox first with position: fixed, then IE

http://tagsoup.com/cookbook/css/fixed/