Try to set TASK_PCT_COMP to 100 via PSI --> not working

Helllo everybody,

I'am working with a Project Server 2010 and the PSI.

At the moment I try to change the TASK_PCT_COMP of some tasks in some projects with the PSI.

There I get the dataset, change the values and then update the Project.
But then nothing happens. I tryed the same via ProjTool.

The work (TASK_PCT_WORK_COMP) of these Tasks are 100. But the Task_REM_DUR >0 . When I try to change the Task_REM_DUR to the value of TASK_ACT_DUR I get the error "ProjectActualsAreProtected".

In the Project Client this is no Problem.

Can somebody help?

Thanks in advance.

Best regards,

Marc