co-pa enhancement issue.

Hi expert,

           I do a enhancement for my co-pa DS 1_CO_PA800IDEA, I put a new field into enhancement structure of the extract structure. there a question as follows:

1. In enhancement code, I set the new field as capital char 'ZB'. but while I was trying to load this DS into infocub, I got error showing :

'   value 'zb' of character contains invalid character ',  but this error only effective for 5 rows,  how come my capital source field was converted to lowercase? and why this error only occurred for 5 rows ? because this field is filled by contant 'ZB', I think the error should be happened for all rows.

Many Thanks,

andy