Index: spf_vtable.c
===================================================================
--- spf_vtable.c	(revision 25723)
+++ spf_vtable.c	(working copy)
@@ -291,7 +291,7 @@
         real_exception(interp, NULL, INVALID_CHARACTER,
                 "Internal sprintf doesn't recognize size %d for a float",
                 size);
-        return (HUGEFLOATVAL)0.0;
+        //return (HUGEFLOATVAL)0.0;
     }
 }
 
Index: stm/backend.c
===================================================================
--- stm/backend.c	(revision 25723)
+++ stm/backend.c	(working copy)
@@ -916,7 +916,7 @@
 
     if (log->depth == 0) {
         real_exception(interp, NULL, 1, "stm_commit without transaction\n");
-        return 0;
+		//return 0;
     }
 
     PARROT_ASSERT(log->depth > 0);
@@ -1679,7 +1679,7 @@
 
     if (log->depth == 0) {
         real_exception(interp, NULL, 1, "STM_begin_update outside transaction");
-        return PMCNULL;
+		//return PMCNULL;
     }
 
     write = find_write_record(interp, handle, 0);
Index: thread.c
===================================================================
--- thread.c	(revision 25723)
+++ thread.c	(working copy)
@@ -285,7 +285,7 @@
     if (type_num == enum_type_undef) {
         UNLOCK_INTERPRETER(master);
         real_exception(interp, NULL, 1, "pt_shared_fixup: unsharable type");
-        return PMCNULL;
+        //return PMCNULL;
     }
 
     pmc->vtable = master->vtables[type_num];
@@ -1307,7 +1307,7 @@
     UNLOCK(interpreter_array_mutex);
     real_exception(interp, NULL, 1, "join: illegal thread state %d tid %d",
             state, tid);
-    return NULL;
+    //return NULL;
 }
 
 /*