[Zope] can't add back "title" to object?

[Chris Ryland]

I've got a folder from which I (mistakenly) deleted the "title" property.

When I try to add it back (title / string / <string value>), I get a Zope
error: "Bad request / invalid or duplicate property id".

This is probably a Zope-for-Dummies-style question, but I'm a little
stumped. (A quick Google search turned up nothing, though perhaps I'm not
looking correctly.)

Thanks for any help.
--
Cheers!
Chris Ryland
Em Software, Inc.
www.emsoftware.com