Adding CalendarStore.framework changes managed object model version?

FROM : Brad Willoughby
DATE : Wed Mar 26 01:56:28 2008

When I add /System/Library/Frameworks/CalendarStore.framework to my 
Leopard Core Data application in XCode 3.0 and click Build & Run, I 
get the following error:

"The managed object model version used to open the persistent store is 
incompatible with the one that was used to create the persistent store."

This makes no sense to me.  I have not touched my data model and can 
confirm that it has not changed via subversion's "svn status".  I 
Googled and checked the cocoa-dev archives, but there's not much out 
there regarding the Calendar Store framework.

Any ideas as to why adding CalendarStore.framework is causing this 
Core Data error?

Cheers,
Brad
TinyPlanet Software, LLC
http://tinyplanetsoftware.com/