I painted 2 ceilings first the bathroom which came out perfect, the second the lounge room but for some reason the lounge came out chalky in one area where the light comes in the window. I used Taubmans easy coat for both rooms and a decent brand roller. I have done 4 coats now in the lounge thinking it would get better but it's still the same. The paint in the lounge prior to painting had no defects. Anyone know why this has happened and how to fix?