Purchase requisition workflow

[Amit (Intelligroup)]

Hi All,
We are using purchase requisition workflow; although things were moving well
and fine in our development but have take a very different shape in quality.
 
As per the release process when value of PR exceeds certain limit it is
forwarded to relevant persons in the release group thus maintained in the
IMG configurations. Although work item is going to the right person in the
first level of release process but in the second level of release two
workitems are created which are routed to 2 different users one of it
defined in the IMG configurations and other one who is neither mapped in HR
hierarchy nor maintained in the configurations.
 
While workflow log shows only one user as a possible agent for the task.
When I tried to execute the workitem from one of the inbox it got
disappeared thus changing   the overall status of the workflow as completed.
 
While on the other hand when I had tried to execute the work item from the
inbox of other agent. I can found an error message in error log - Processing
cancelled by the user.
 
Am unable to comprehend that what all  is going in the same.
 
Any help and suggestions are welcome.
 
Regards
Amit