Turns out the javascript I was using was version 1.2, not 1.1. Who knew?

webtools/bugzilla/query.cgi

@@ -187,7 +187,7 @@ my $emailinput2 = GenerateEmailInput(2);
 # javascript
     
 my $jscript = << 'ENDSCRIPT';
-<script language="Javascript1.1">
+<script language="Javascript1.2">
 <!--
 var cpts = new Array();
 var vers = new Array();