Error when running vifp addserver

When I run vifp addserver <server> it asks for the root password to which I give the correct root password to the host.  It then reports:

Error: An error occurred while creating users ons <host>

It seems to add user vi-admin00, but not vi-user00, base on another host on another VCeneter.  The one without the problem is running ESXi 4.0.  This one is running ESX 3.5.

We are not seeing events or anything else to indicate where the problem is.

Any help would be appreciated.

Thanks,

Mel