Index: src/GenPoly/InstantiateGeneric.cc
===================================================================
--- src/GenPoly/InstantiateGeneric.cc	(revision f0ecf9bfb3ccc333894542767cb1c491f7e79993)
+++ src/GenPoly/InstantiateGeneric.cc	(revision 136ccd79f8c610f8bde4fbe2e065362de2680188)
@@ -278,5 +278,6 @@
 		substituteMembers( base->get_members(), baseParams, typeSubs );
 
-		deleteAll( baseParams );
+		// xxx - can't delete type parameters because they may have assertions that are used
+		// deleteAll( baseParams );
 		baseParams.clear();