Products per row

Hi,

I am unable to change the number of products per row using the following code:
// Change number or products per row to 3

add_filter(‘loop_shop_columns’, ‘loop_columns’);

if (!function_exists(‘loop_columns’)) {

function loop_columns() {

return 3; // 3 products per row

}

}
I am using sommerce shop theme.
The items appear 4 in a row in 1st row then 1 on 2nd row , again 4 items on 3rd row and 1 on 4th ….
It looks awkward.However when i use a sidebar that code works , but i don’t want a sidebar on my shop page.
Please help.

http://wordpress.org/extend/plugins/woocommerce/