An online retail company is using Edgecast's CDN and somehow certain CSS files are continually being 'half loaded' into cache, ie. It loads half the file into cache and then stops (as if it is interrupted) at a point. So the cache then serves this incomplete file as the new legitimate cache and users see a 'misshaped' front end. This problem remains until the support team manually clear the cache and it loads the full CSS file correctly.
The CDN support team point to the app devs, and vice versa.
Could anyone suggest any troubleshooting, or how to track down whether it is the App or the CDN causing such an error?