google analytics not working for pop up PDF

I've been trying to fix google analytics on a school website for a while now and I can't figure out what's wrong. All I am tracking is link clicks. Links to other websites track just fine, but links to pop ups don't work. I have a pop up of a PDF specifically for an example. It seems like the onClick portion is never executed since "TestTab" never shows up as an event category. The google analytics portion is the same here as it is in other places where it works just fine. I would appreciate any help with this.

<a href="popups/SummerPositionsMay11.pdf" 
   onClick="_gaq.push(['_trackEvent', 'TestTab', 'CurrentStudentEmploymentOpportunities']);"
   rel="clearbox[gallery=Resources,,width=600,,height=400,,title=Open Positions]">
      Current Student Employment </br> Opportunities
</a>