My replacement windows move within the window frame and I was wondering if this is normal. Only a couple of the windows fit snug, but the others can be jiggled either pressing against them, pulling on the handle at the lower part of the window, or holding the top of the window frame. This is happening when the windows are locked and closed. I was told by Anderson that this is normal and they are still airtight, but I don't believe it. Can anyone comment on this?