[hebs]

for 4.1.9

in skin1/check_cc_number_script.js

Replace:

function checkCCNumber(field_cc, field_accepted) {
    var cc = field_cc.value;
    var accepted = (field_accepted != null) ? [card_types[field_accepted.value]] : null;

    if (isCreditCard(cc, accepted))
        return true;

    alert(txt_cc_number_invalid);
    field_cc.focus();
    field_cc.select();
    return false;
}

with this (as per 1st post):

function checkCCNumber(field_cc,field_accepted) {
    var original_cc=field_cc.value;
    var cc=field_cc.value.replace(/[^\d]/g, '');
    var accepted=null;
    if(field_accepted!=null)
        accepted=new Array(card_types[field_accepted.value]);
    if (isCreditCard(cc,accepted)){
        field_cc.value = cc;
            return true;
      }else {
        alert(txt_cc_number_invalid);
        field_cc.focus();
        field_cc.select();
        return false;
    }
}

works great!