WordPress Gallery images displaying vertically

Hi,

My WordPress image gallery is now displaying improperly. Thumbnails are stacked vertically, rather than 5 across as specified in the shortcode.

It looks perfect in Firefox, but displays incorrectly in Chrome and Safari.

I have not changed any plugins/content of the website before this problem occured, I suspect it is the latest update to WordPress. I am currently running 3.9.

Here’s the shortcode:

[gallery columns="5" ids="1656,1655,1660,1657,2715,2279,3344,2153,1881,1584"]

The page:

http://lindastein.com/new/series

Please help!