Hi Steve, I ran into a very tricky problem when developing a site with emarket. Here is the structure of my site: root |--acl_users(Membership product) |--emarket |--shoppers The acl_users is an instance of Membership product, which is as a specialist as shoppers, and they both have a WebIC_MemberClass zclass as their rack object class. The difference is that, acl_users stores WebIC_MemberClass persistently, while shoppers just reflects that storage. Here is the skinscript for shopper's rack: WITH acl_users.getItem(self.id) COMPUTE oo=RESULT WITH self.oo COMPUTE email, transCount WHEN OBJECT CHANGED STORE transCount USING self.oo.propertysheets.webic.manage_changeProperties(transCount=self.transCount) When emarket trying to increment a shopper's transCount, I ran into a "ZODB.POSException.ConflictError". The following is the traceback: Traceback (innermost last): File C:\WebSite\lib\python\ZPublisher\Publish.py, line 222, in publish_module File C:\WebSite\lib\python\ZPublisher\Publish.py, line 199, in publish File C:\WebSite\lib\python\ZPublisher\Publish.py, line 199, in publish File C:\WebSite\lib\python\ZPublisher\Publish.py, line 199, in publish File C:\WebSite\lib\python\ZPublisher\Publish.py, line 195, in publish File C:\WebSite\lib\python\Zope\__init__.py, line 188, in zpublisher_exception_hook (Object: ProviderContainer) File C:\WebSite\lib\python\ZPublisher\Publish.py, line 175, in publish File C:\WebSite\lib\python\Zope\__init__.py, line 235, in commit File C:\WebSite\lib\python\ZODB\Transaction.py, line 251, in commit File C:\WebSite\lib\python\ZODB\Connection.py, line 351, in commit (Info: (('*hdVMVCvgk/wIgJaYf/nkEA==', 'WebIC_MemberClass'), '\000\000\000\000\000\000d\357', '')) File C:\WebSite\lib\python\ZODB\FileStorage.py, line 664, in store (Object: C:\WebSite/var/Data.fs) ConflictError: ('\0039\323C4=\266\210', '\0039\323B\375\036\270U') Is it something wrong with my skinscript? cheers Dirksen __________________________________________________ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/