=== modified file 'bin/addons/base/ir/workflow/print_instance.py'
--- bin/addons/base/ir/workflow/print_instance.py	2009-01-04 22:13:29 +0000
+++ bin/addons/base/ir/workflow/print_instance.py	2010-05-03 11:32:24 +0000
@@ -82,6 +82,8 @@
     start = cr.fetchone()[0]
     cr.execute("select 'subflow.'||name,id from wkf_activity where flow_stop=True and wkf_id=%s", (wkf_id,))
     stop = cr.fetchall()
+    if not stop:
+        return ((start,{}),)
     stop = (stop[0][1], dict(stop))
     return ((start,{}),stop)