s0ulsurfing on "[Plugin: Ultimate Tag Cloud Widget] No cloud, just a long line"

Hi,

I'm using Ultimate tag cloud widget v2.1 on a site with wordpress up to date and using 3.5.1

http://flypapertextures.com/tag-cloud/

It displays Fine in Chrome, but is just displaying as one long line when using firefox
Firefox (19.0.02)

any help please?

http://wordpress.org/extend/plugins/ultimate-tag-cloud-widget/