Air infiltration in Thermal Industries windows
A couple months ago we had two large sliders installed (each with a fixed window in the center) along with two double hungs from Thermal Industries. We have since had noticeable air movement coming in along the bottom rails where the sliding portion meets the fixed portion in the sliders. A draft from three feet away was also felt from one of the double hung windows! Thermal Industries "solution" is to come out and add more weatherstripping along the rails. Does this seem like an adequate (and professional solution)?
Is there any other way to resolve this, or are these just not quality windows and they'll never be ok?