Exchange 2010 sp3 upgrade error - AD references to old 2003 server

I've just tried running the SP3 upgrade for a clients Exchange 2010 server, so I can start a hybrid deployment with 365. The SP installer has come up with an error referring to the old 2003 exchange server and its public folder database. The client doesn't use their public folders much, so if they break its not a big deal but will there be other repercussions? Infact I'm not 100% sure what I need to be deleting in ADSI Edit as I can't find a "Property Name: PublicFolderDatabase".

The following error was generated when "$error.Clear();
      initialize-AdminGroupPermissions -DomainController $RoleDomainController" was run: "Object First Administrative Group': the linked object of property 'PublicFolderDatabase' is '<domain>.local/Configuration/LostAndFoundConfig/EXCHANGE1/InformationStore/First Storage Group/Public Folder Store (EXCHANGE1)', which doesn't exist in First Organization '<domain>'. This might be because the object is corrupt in Active Directory. Please set a valid value for this property. Property Name: PublicFolderDatabase".