"Currently, Amazon only collects sales tax in Kansas, Kentucky, New York, North Dakota and Washington. Starting July 1, Texas will be added to that list. Amazon also agreed to start collecting sales tax on online items in California starting next year, and in Arizona in 2014."

Excerpted from: http://www.dailytech.com/article.aspx?newsid=24571 

States need revenue so expect more and more to start playing hardball with online retailers and retailers charging. I don't know if DAZ has any presence in Califas. As moriador said, it may be the new store software. Only way to fuind out is to ask them :-) 

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken