Workflow Stops without error

[michael.porter]

Dear All
 
I wonder if anybody has experienced a problem where active workflows
cease to continue following the WI_ID being deleted.
 
I have had this in several instances and all I can gather from the
technical log is that the WI_ID has been deleted from the database.
Obviously this has caused the workflow to go no further, the question
I can't answer is why this occurred.
 
The only theory I have is that a function Module has been triggered
by a system reboot and performed the deletion. However it has not
affected all open workflows on the same template in the same date
period!
 
Regards
 
Mike Porter