Problem on assigning task list in Maintenance Order

Hi,

I am getting a unique error in task list...

Scenario is that i have maintained general task list with work updated in it and there is no calculation key maintained in it.

Now, when i assign this task list to a Maintenance Order it shows work hours as mentioned in the task list....

But when I save it and again open the order then work hours comes as 100 irrespective of the value maintained in task list.

Now, if i assign another task list which has calculation key assigned to it then there is no problem.

Can anyone please help me on this.

Thanks & Regards,