Notification of completion cannot be generated

["Schröder, Ute Marion"]

Hallo all,
 
might be not a real workflow problem, however I=B4ve=20
decided to give it a try and ask the experts.
 
During execution of a workitem (the last one in our workflow), I =
sometimes
receive
the error message: Notification of completion cannot be generated.
The anoying thing is, it happens not regularly. Many workitems can be
completed
normally before some of them get the error (wf are created in a similar
way).
Anyone any idea where I=B4ve made my mistake?
 
Thanx
 
Ute