diff -r 42693fe3ef6f -r bccd9a788f7a server/msplanner.py
--- a/server/msplanner.py	Tue Jan 13 17:51:54 2009 +0100
+++ b/server/msplanner.py	Tue Jan 13 17:55:29 2009 +0100
@@ -364,6 +364,8 @@
                 # can't get information from relation inside a NOT exists
                 # where variables don't belong to the same scope
                 continue
+            if not (var.scope is rel.scope and ovar.scope is rel.scope) and rel.ored():
+                continue
             relsources = self._session.repo.rel_type_sources(rel.r_type)
             if rel.neged(strict=True) and (
                 len(relsources) < 2