If you're lucky, then something on this page is doubleclickable..
doubleclickable radio button

NS4.5/Unix: No effect whatsoever, with any of the above
IE: they all work, except for the submit-button

double click should show an alert

NS4.5/Unix: No way
IE: neither

at least with a target leading somewhere else, double click should show an alert

NS4.5/Unix: Still no way
IE: only if the target window already exists