Thumbnail Problem

This theme Currently i am using is from free source and now i changed it to my self owned theme and again this same problem occurs, you can crosscheck by going to http://www.deepanker.in
i don’t think this is coding part issue because i had tried it with couple of themes(self owned and free). all themes can’t have a same issue.

If this is due to coding part in theme, so would you let me help out of how can it be solved?

ok. i am now changing it to the default theme to twenty twelve as you have said. but i think that twenty twelve theme doesn’t support thumbnail like designs

SO what do you guys think how can this problem be resolved?

Thanks