project server 2010 psi issue?

Hi :

We are currently on project server 2010, Sharepoint 2010 and sql server 2008 r2.  I created a project to update actual work in assignment using psi call.  I ran into an issue with two projects.  I stepped through the project.  It updated the expenses. But it never published the project.  I received the following error message. 

<?xml version="1.0" encoding="utf-16"?>
<errinfo>
  <dataset name="ProjectDataSet">
    <table name="Assignment">
      <row ASSN_UID="xxx" PROJ_UID="xxx">
        <error id="1047" name="ProjectActualsAreProtected" uid="xxx" />
      </row>
    </table>
  </dataset>
  <general>
    <class name="Queue">
      <error id="26000" name="GeneralQueueJobFailed" uid="xxx" JobUID="xxx" ComputerName="xxx" GroupType="ProjectUpdate" MessageType="ProjectUpdateMessage" MessageId="2" Stage="" />
    </class>
  </general>
</errinfo>

The strangest thing is if we go into pwa.  Then go to server setting.  Select Task Setting and Display.  Under protect user updates.  If we uncheck Only allow Task udpates via Tasks and Timesheets.   The project will run with no problem.  If we enable it again.  We will keep on receiving the error message that is shown above.   It only happened on these two projects.  The rest of the projects are fine.   We are not sure whether we should enable it or disable it.    Any ideas?  Is there something we need to change within these two projects ? What will cause this issue?

Thanks,

kkmick