Ctrl Space autocompletion

Recently it was pointed out to me that I can use Ctrl-Space to 
automatically complete some items.  For example if I forgot if the bif for 
substring was %SST or %SUBSTR or %SUBST I could type in %S and hit 
Ctrl-Space and it very quickly pops up a little window to assist me.

I thought I read that it would help me autocomplete variables also.  For 
example if I had
     D JulianDate      s               d   datfmt(*jul)

I could be typing in the following area:
      /free
       *inlr=*on;
       Jul     and hit Ctrl-Space here and it would fill it in.
However, that doesn't seem to work.  Did I read it wrong, or am I doing it 
wrong?

Version: 6.0.1
Build id: 20050725_1800

Rob Berendt