webMethods 7.1.1. TaskClient API bug with cancelTask()

While cancelling a task which is active, we are using 2 webMethods built-in API/Services to cancel tasks…but the API/IS service cancels the task but it also creates another junk task by the name Administrator

Original CAF code had only below Step
As a workaround i have these 3 steps to fix the problem

the same is happening while using TaskClient IS service to cancelTask… I have to explicitly set some junk value instead of cancelled to TaskInfo document and then call cancelTask service to fix the Junk being created as a result of cancling actual task.

Has anyone seen this problem with 7.1.1 and are there any fix for this ?