Themes not working in Mozilla/Firefox/Chrome

Hi all,

I’ve been testing a few different themes out and I noticed that Mozilla is displaying them abnormal. Once I noticed this, I switched back to the classis and noticed the same issue. In Firefox, a few of my last posts overlap each other. I also have 3 rows of categories listed on the top of my page (header) and in firefox it only displays the first line while the other 2 are hidden behind the border. Also a couple of my sub-pages/category pages are misaligned.

Everything displaying perfectly in internet explorer. I’m having the exact same issue with Mozilla and Google Chrome as well.

Anyone come across this before and have any suggestions?

Thanks