I found that vbulletin_menu.js is not being included when the page is loaded in Chrome, and I think it has to do with this code in global.php:
HTML Code:
if ($vbulletin->options['usepopups'])
{
if ((is_browser('ie', 5) AND !is_browser('mac')) OR is_browser('mozilla') OR is_browser('firebird') OR is_browser('opera', 7) OR is_browser('webkit') OR is_browser('konqueror', 3.2))
{
// use popups
}
else
{
// don't use popups
$vbulletin->options['usepopups'] = 0;
}
}
I have version 3.8.3 which isn't the latest. Maybe the cases in the "if" don't include Chrome. But that's kind of confusing because it would mean they would never work in Chrome, but I don't think I've ever seen anyone ask about this before.
ETA: ...also Joe just said he has no problems, so maybe the code above isn't the issue. But in template headinclude there's a if $show['popups'] around the line that includes vbulletin_menu.js, so I'm assuming $show['popups'] is set to false for some reason.
More Edits: I notice that your site is using 3.6.4, maybe that version is out of date when it comes to detecting browsers.