I'm dumbstruck...
It would seem that you can not trigger a double click event on a single line selectbox in modern browsers... I've been able to do this on 'old' IE8, but when upgrading a webapp to IE 10 it this just stopped working... Also testen FF, same problems.
check this fiddle: http://jsfiddle.net/vLnA2/
<SELECT ondblclick="go()">
<option value="1">1</option>
<option value="2">2</option>
</SELECT>