Sakurai Oliver 266 EPZ Mis-Fed Sheet fault

Hi There....
We are having problem with our Sakurai Oliver 266 EPZ machine. It get stopped a few moment after sheets were transferred from feeder. The lcd monitor showing "Mis Fed Sheet" message, even there weren't any papers miss-aligned. We tried to check the 2 feeding optic-sensors signals on input module, it's OK (signal ON). The signal was tried to be forced in true logic (24V) to make sure the feeding signal wasn't in problem, but machine still remain in problem.
Is there anyone have the same/known this problem? Please let us know.
Thank's