Media Object Error Using Performance Management

We are on E8.12 Tools 8.98.1.2 and using Performance Management. We are trying to replace our existing traditional appraisal template WORD 2003 (.doc) files with EXCEL 2007 (.xlsx) files. When the employee submits their self-appraisal to their supervisor, or the supervisor submits the appraisal to the next level, a media object error window displays the message "changes made to this read only OLE object will not be saved” , requiring the OK button to be clicked. We also get the normal application confirmation window at same time. If we click OK to media obj msg, app works as expected with