Products not showing properly

Hi everyone.
My store has a default number of products per row set to 4 and its displaing ok on large screens but as soon as the browser window is resized to smaller size the products are all over the place.
3 products in one row and only one in the second row following 3 products in another and so on as seen here: http://tinypic.com/r/30upeg4/8
Is there a way to make the products show in the same numbers per row as the browser window gets smaller, for example 3 per row in every row, then 2 per row in every row, you get the idea i hope.
Thanks in advance for any advice or suggestion.

https://wordpress.org/plugins/jigoshop/