Test shows unablt to connect or 404 for main stylesheet

Hi,
I have been successfully using webpagetest to evaluate a site and improve the site load. Over the past 48 hours, I have either been receiving an error failed to connect, or when I get a full waterfall, the main theme’s style.css is showing as a 404 error. This is strange as the files can be accessed through the direct urls (note that the sites is using a child theme, and it is the main stylesheet that is showing the errors).

Any ideas why this might be happening?
Barnez

Site

http://www.proofscience.com/wp-content/themes/breakout-child/style.css[b]
http://www.proofscience.com/wp-content/themes/breakout/style.css[/b]
http://www.proofscience.com/wp-content/themes/breakout/css/theme.css

Waterfall
http://www.webpagetest.org/result/130503_TQ_TN5/1/details/