Chris, as a quick fix try this. This seems to make it work similar to old navy.
In your minicart.js add the window.scroll(0,0);
Code:
popup_onfocus: function() {
// set the flag that the current focused area is the minicart panel
this.popupFocused = true;
window.scroll(0, 0);
},
Ive tried it and it worked in IE, it doesnt work in FF but right now for me the ajax minicart in FF isnt expanding at all when I add something.
At any rate, this is a quick fix .... the ultimate is something like Alkaline or Vortx has .. those are both nice solutions.
Please let me know if this works for you.