RichN wrote an answer about The North Face Varius Guide Jacket - Women's on January 6, 2012
All the vests that my wife owns zip in. (Nuptse, and Thunder) The trick is to make sure the zipper mates completely as far as it goes. There are two zippers on the shell, the one that attaches to your vest is inside and bigger than the main shell zipper. What helps is, wear the vest with the front open and attach it. Hope that helps.