PaymentProcessor_PreventMultipleDefaults.trigger not functional

[njjc]

PaymentProcessor_PreventMultipleDefaults.trigger doesn't allow editing the current default record; trying to save after an edit throws "Error:You have already selected a Payment Processor as the Default Processor. Please uncheck this option to save this record."

[njjc]

I believe this should work:

trigger PaymentProcessor_PreventMultipleDefaults on gwop__Payment_Processor__c (before insert, before update) {

    //first query to see if there is a default processor
    Payment_Processor__c[] processors = [SELECT id FROM Payment_Processor__c WHERE Default_Connection__c = true];

    if (!processors.isEmpty()) {
        for (Payment_Processor__c p : trigger.new) {
            if (p.Default_Connection__c && (trigger.isInsert || p.id!=processors[0].id)) {
                p.addError('You have already selected a Payment Processor as the Default Processor. Please uncheck this option to save this record.');
            }
        }
    }

}