Either you have the business object in Edit or Add mode or the business object is somehow getting dirty (some property set is firing) and making the business object dirty.
To figure out what's causing it, add a handler to the business object's IsDirtyChanged event and put a break point in the handler. When the break point is hit, check the call stack and you should be able to figure out what caused the business object to think that it's dirty.
If you have either of these set and add a new record, you generally get the behavior you are experiencing. I would imagine that some type of filter or set is set.
I know it is a cowboy's table, but "cow_lastname" and "cow_firstname" sounded really funny for me...
I'm Brazilian, it is not my fault to be silly like this...