I need your expert help. I recently bought a Perma-Shield patio sliding door from Anderson Windows. The problems I have been experiencing are that whenever there is rain (and not just strong wind-driven storms), moisture appears inside the house in the "sill tank" at the bottom of the door; furthermore, during the winter I feel a cold draft coming in from the bottom of the door from the same area that is allowing moisture indoors. I suspect that if a cold draft is coming in during the winter, that I will be experiencing heat entering in the summer. I contacted Anderson Windows and their response to me was that the sliding door is designed to behave in the manner I described above. I really find this hard to believe, it’s so counter intuitive. The reason I bought a new sliding door was to keep out the rain, cold and heat - not to invite it indoors! Could you please opine - have you ever heard of this situation before? Are Anderson’s claims valid?