1/2 of post before pagination disappeared

i like this theme.
dear alex much love from me.

but at my home page,there is irregularity with the last two post before the pagination, only 1 post is appearing,leaving a blank white space to the right.

i.e after the featured post,the next posts ought to be 2 post thumbnail and execept being side by side of eachother,when you scroll down,but my websites using the theme only 1 appear before the pagination how can i make sure that before pagination there should be two post there?