Recent posts shortcode inside one_third column problem

On the homepage I want 2/3rds image and 1/3rd last post. I can do this fine, but on the 1/3 last post the text is restricted to a very small area, which is putting 1 word on each line. There’s lots more space for the text to flow into, but for some reason it’s dropping each word onto a separate line. Again this is all without adding any custom css.

The recent post shortcode does this when used with any column shortcode.
I’m using…

[two_thirds]
homepageimage
[/two_thirds]
[one_third_last]
[recent_posts type=”post” count=”3″]What I’ve written recently[/recent_posts]
[/one_third_last]

Any ideas?