Jetpack Tiled Gallery Width Issue

Per the many solutions to the Jetpack Tiled Gallery Width issue, I added the following to my functions.php:

if ( ! isset( $content_width ) )
$content_width = 610;

This worked perfectly…in Firefox. Yet, when I pulled up the pages on Chrome or Safari, all heck broke loose and I had major formatting issues. I don’t know much about code, but on the surface this doesn’t make sense to me.

Any suggestions??

http://ww.wp.xz.cn/extend/plugins/jetpack/