can't create IMAP folders

I have 3 different WebMail programs that use PHP 4.0.2 to connect to the PMDF 5.2-31 IMAP server 1.3.1. When the user connects the first time, a file called PMDF_IMAP.MAILBOX is created, but it is a 0/0 file. When the user tries to create a folder via IMAP, a folder name and corresponding .UID is entered into the MAIL.MAI-UIDDIR file, but not the PMDF_IMAP.MAILBOX, and there is no actual corresponding .UID file. Once a folder actually exists, let's say 'test' (made with some other program) and you hand-edit PMDF_IMAP.MAILBOX to include the value test= all is well and the user can go about creating or deleting folders. There are Perl and Pike-based programs that allow users to successfully create folders via the PMDF_IMAP.MAILBOX system . . . I do neither VMS, nor PMDF, nor PHP--I'm the Unix sys admin trying to install a package that checks mail on a VMS server elsewhere in or organization, so I'm not sure where to start . . . Melissa Anderson <anderson_me@4j.lane.edu>