Joel installed a bug fix for the help browser on redhat 5 machines. (new sirius, new mirzam). As of 13 Feb 2009, it is installed on all three licensees (incl algol).
If you use idlde, it is transparent.
If you use command line idl, you have to type idlhelp before typing idl
Joel had to contact idl support to find out about it. For ref, XULRunner patch for IDL 7.0,http://www.ittvis.com/services/techtip.asp?ttid=4395