Can't find gregoriantojd in PHP 5.2.6

Hi all,
    Something has gone wrong with our linux PHP 5.2.6 installation.  
Despite enable-calendar being turned on, at least some of the calendar 
functions cannot be found.  In particular gregoriantojd is not found 
when I call it.  This in spite of the fact that my old PHP installation 
had this function.  Does anyone know where this function might be found 
or what we are doing wrong?

    Apologies if this message is being repeated.  I have been having 
some trouble getting through to the list.

Mary Anderson