I have a custom object with a "Set Default" Checkbox to indicate that that record is the default record for another process.  Obviously I only want one default record at a time.  I am writing a trigger to set all the other records checkbox to false when a new or updated records checkbox is set to true.  Here is my Code:

trigger SetDefault on Workflow_Types__c (before insert, before update) {
    
    List<Workflow_Types__c> wt = new List<Workflow_Types__c>([Select id, default__c from Workflow_Types__c]);
    Integer size = wt.size();
    for (Workflow_Types__c w: Trigger.new){
        if (w.Default__c == True){
            for (Integer i = 0; i < wt.size(); i++){
                if (wt[i].id != w.id){
                    wt[i].Default__c = False;
                    //update wt[i];
                }else{
                    Workflow_Types__c temp = wt.remove(i);
                    system.assertEquals(w.id, temp.id);
                    system.assertEquals(wt.size(), size-1);
                }
            }
        }
    }
    update wt;
    
}

 The problem is that even though I am trying to remove the record that calls the trigger and the assertions are passed for some reason it is still trying to recursively update the calling record when I call update wt, and gives me an error.  If I uncomment the line //update wt[i]; and comment the other update it does work, but I am afraid of possibly hitting governor limits by putting the DML statement in the for loops.  Any ideas would be appreciated.

Thanks

Edit: I have determined that the behaviour I described only happens when there are only two records in the object.  If I add more objects I have no problems