[Theme Twenty Twlelve] Article text bunched together

Hello;

I am using theme Twenty Twelve v 1.1.
The text of individual articles are all bunched together: line breaks, and new paragraphs are being removed and the text appears as one huge block. Doesn’t look good and isn’t easy to read.

How do I fix this? I checked the style.css file for a possible adjustment but unless I overlooked it, I can’t seem to find anything that removes line breaks,
, <P> (it only does that in the single post).

Thanks

Lode