I'm trying to find a solution to this. I have a C3PO addin to groupwise that creates new contacts in your address book from an external source using the object api.

I can create all fields on a contact just fine, except for the Suffix field.

When I try to add the Suffix field to a contact, it always generates this error:
Error -2147352567(80020009) - Attempt to use undefined field name on item

All other fields (First Name, Last Name, etc) work without a problem.

Our customer is getting really upset about this.

What can I do to overcome this? Is this a known issue?