diff -r d58a9d96aad8 -r 29961a416faa server/sources/pyrorql.py
--- a/server/sources/pyrorql.py	Fri Jun 17 18:50:13 2011 +0200
+++ b/server/sources/pyrorql.py	Fri Jun 17 18:53:33 2011 +0200
@@ -234,6 +234,7 @@
         etype, dexturi, dextid = cnx.describe(extid)
         if dexturi == 'system' or not (
             dexturi in self.repo.sources_by_uri or self._skip_externals):
+            assert etype in self.support_entities, etype
             eid = self.repo.extid2eid(self, str(extid), etype, session)
             if eid > 0:
                 return eid, True