Activemenus break when Site Pass module is enabled.

It's as simple as that. When Site Pass is enabled, Activemenus stop working. Turn Site Pass off, and they begin to work again. Here's what Firebug tells me:

arg has no properties
e([undefined])jquery.js (line 2)
e([undefined], true, 1, function())jquery.js (line 2)
e()jquery.js (line 2)
success(Object status=0)activemenu.js (line 54)
e(undefined)jquery.js (line 2)
[Break on this error] eval(function(p,a,c,k,e,d){e=function(c){return(c

and here's where you can find the site pass module:

http://drupal.org/project/sitepass

I suggest you apply this patch as well:

http://drupal.org/files/issues/no_bcmath.patch