diff --git a/checkin_notes b/checkin_notes
index 1cb05fa94c..5cc567116c 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -5727,3 +5727,9 @@ David  16 June 2009
     Makefile.am
     lib/
         Makefile.am
+
+David  16 June 2009
+    - python assimilator fix
+
+    sched/
+        assimilator.py
diff --git a/sched/assimilator.py b/sched/assimilator.py
index 8dd4b37c0e..865cdb9372 100644
--- a/sched/assimilator.py
+++ b/sched/assimilator.py
@@ -180,9 +180,13 @@ class Assimilator():
                 if result == wu.canonical_result:
                     canonical_result=result
     
-            if canonical_result == None:
-                # something is wrong, flag an error
+            if canonical_result == None and wu.error_mask == 0:
+                # If no canonical result found and WU had no other errors,
+                # something is wrong, e.g. result records got deleted prematurely.
+                # This is probably unrecoverable, so mark the WU as having
+                # an assimilation error and keep going.
                 wu.error_mask = boinc_db.WU_ERROR_NO_CANONICAL_RESULT
+                wu.commit()
                 
             # assimilate handler
             self.assimilate_handler(wu, results, canonical_result)