I am currently working on the same problem.  I won't know if I have the
solution
until tomorrow though.  When you set password generate, the node
automaticall
generates and stores a new passwd when the old password expires.  When you
set
up the node you had to supply some kind of password with it.  In order for
the
node to generate a new password the old one has to expire and I don't know
of a
way to force this, so I've set my passwords to expire after one day.  If
anyone
thinks I'm way off base with this please let me know because I am just
winging
it.

Richard