These are set correctly as 3 and when you go to the all products, special products, new products etc. links in the category side box the products show up in three rows. The problem is that on the opening page and other category pages the boxes below which are labeled Newest, Specials and Featured are all in single column not 3 across,
Frank
Had similar problem but only with Featured Products - turned out to be related to previous template (Winchester Black Responsive) that had a setting in the admin/config and database that is not used in Responsive Sheffield Blue - but the old setting remained in database and interfered. If this sounds like might be your case, check post #756 in this forum for how I fixed.