>> Zac Posen's Spring 2010 Venue Switcheroo Causes Retailer Grief? —Zac Posen switched the big Tent at Bryant Park for the much smaller Altman Building this season — because it was better for the collection, not for financial reasons, he says — and this morning he had everything set up like an old fashion show: round areas of chairs, with the models posing and spinning for each section; Tiiu Kuik walked (left) — her first time on the runway since the Fall 2008 season.  But later today at Carolina Herrera, a rumor was floating around that a few major retailers boycotted Zac's show because it wasn't handled as efficiently as usual . . . [The Cut Twitter, StyleWriterNYC Twitter]