[Koha-devel] User info modification

Hi I'm having problems with Koha (CVS version) trying to modify properties of a borrower. We're using cardnumber like 00A000. The cardnumber field in the borrower table is reported as a varchar(9) so letters shouldn't be a problem. The fact is, when I try to modify properties, when applying changes, Koha tells me that my cardnumber is invalid ! Is this a local problem ? I've tried with digits only and still had the same problem. By the way, I want to change the mandatory fields in the user info page. Is there a way to change it ? If so where ? Thanks Jerome