[gentooppc-user] courier-IMAP ${MAILDIR} not getting set

[linux_box]

Code listing 49 of the gentoo desktop users guide
has a hilited section which refers to this, but
that reference is very confusing to me...When I do what it says, IMAP 
cant see where it should be homed.
If I hardwire a directory, it all works perfectly.

I know ${MAILDIR} is supposed to get loaded with the users $HOME,
but I cant trace how. My IMAP client tells me the ${MAILDIR} var isn't 
getting loaded at all (unless i hardwire/replace the variable).

Any help greatly appreciated!
thanks