[Zope] zope221b1 - broken zclass instances

[Dr. Ross Lazarus]

zope220 working fine, redhat 6.2, intel hardware.

Installed zope221b1 (tried installing the upgrade tar over a copy and
compiling - repeated with the source tar - same results).

All zclass instances broken - the zclass products are healthy looking in
the Products folder and new instances added under 221b1 seem healthy -
it's just all the existing ones which appear broken.

Tried deleting and then importing fresh .zexp versions of the folders
containing my zclass instance - the .zexp file imports fine but the
contained instances are still all broken.

Stopped futzing. Back to zope220 for now.

Is it just me ?