Help with Posts Layout. Posts Lay on top of each other?

Hiya,
Firstly would like to say thank you! for your Lovely Theme goes great with my Site :).

Just has ran into a little Problem, when I go to do another Post, it lays on top of My 1st older post, so you can’t see my New post, as its underneath my Old Post. if you catch my drift… I cant seem to figure out where to put a margin, to space out the posts which displays on my Home-page.

Been tying for a whole day yest, to no avail 🙁
any Suggestions on how to solve this minor problem?

Many thanks! in Advance 🙂