Import Error - No module named zmsgraphic

Dear ZMS-Developers,

I want to transfer a zms-instance from from server to another ...

old server runs Zope 2.10.5, Python 2.4.4, ZMS 2.13.4 Build 1669
new server runs Zope 2.10.13, Python 2.4.6, ZMS 2.13.4 Build 1669

I exported the zms-instance from old server as zexp-file and put it in
the new servers import dir.
but on import via zmi I get the following error message:

Request URL    http://myserver_url/manage_importObject
Exception Type    ImportError
Exception Value    No module named zmsgraphic
Traceback (innermost last):

Module ZPublisher.Publish, line 119, in publish
Module ZPublisher.mapply, line 88, in mapply
Module ZPublisher.Publish, line 42, in call_object
Module OFS.ObjectManager, line 610, in manage_importObject
Module OFS.ObjectManager, line 627, in _importObjectFromFile
Module ZODB.ExportImport, line 75, in importFile
Module transaction._transaction, line 312, in savepoint
Module transaction._transaction, line 309, in savepoint
Module transaction._transaction, line 737, in __init__
Module ZODB.Connection, line 1048, in savepoint
Module ZODB.Connection, line 519, in _commit
Module ZODB.ExportImport, line 143, in _importDuringCommit
ImportError: No module named zmsgraphic


How can this be solved?
Any help appreciated!

regards, Thorsten