I'm assuming it's coming from the outside in. The only time I notice the doors leaking is when the rain comes from the east and it's heavy/steady. I'm also assuming that this is what made my first sets of patio doors leak. I had three sets of patio doors that were steel and all of them rusted. I now have 3 new sets and don't want the same to happen to them. It did happen before the stucco was sealed. Can the stucco have remained too wet for the sealant to have had any effect? It seemed like it had gotten better, but now I'm wondering if maybe it just didn't rain that much that year from that direction.