[jkd]

Perhaps a solution?

<script type="text/javascript">
window.onload = function() {
var newWin;
if (typeof window.popped == 'undefined' || !window.popped) {
newWin = window.open('yourpopupstuff');
newWin.popped = true;

window.location.replace('http://www.google.com');
// maybe history.back() would suffice
}
}
</script>

I basically check to see if you haven't assigned the popup window a boolean, popped. If undefined or doesn't evaluate to true, open the popup code you want, giving the new window the popped boolean. And then, to preserve the main window, replace the location with google's.