K2 and T3, can't adjust category listing , such as two articles in one row

Hi, I use joomla 3.3 and T3 framwork plugin with two templates, and choose T3_bs3_blank template, then install K2.
When I adjust K2>category>layout grid, set the columns for leading to 2(default is 1), the result is not changing! I still see there is one article in one row?
it is T3 issue or other thing, please help, thanks!