Lockbox Sample test --- posting errors

Hi all !

I am running a sample test file for Locbox process and everythign is working fine as its saying customer uniquely identifies by micr number ... but I am getting all of the items as unprocessed and the error message is saying the following for all the items( I am using four checks in my test file and ts showing same message for all the four)

GL posting error (00 298): Formating error in the field COBL- PRCTR

AR posting error(00 298): Formating error in the field COBL- PRCTR

Algortihm 001 error(00 298): Formating error in the field COBL- PRCTR

Could somone throw somelight on this as I need to do this test config urgently.

Thanks

Regards