Problem: Relationship rules are not copied correctly between geodatabases
This problem is addressed in ArcGIS 8.1 Service Pack 1. See Related Information section to download this pack.
When copying and pasting data between geodatabases, the relationship rules are not being copied correctly, in some cases this causes incorrect validation in the resultant database.
This is a known issue.
Solution or Workaround
After copying and pasting, verify and re-establish relationship rules.