I have the same problem. Did you find the solution for it?
In my case the CSS cache stores HTTPS links to the CSS files. But I don’t have a valid SSL certificate. This causes, that while browsing HTTP version of the site, the CSS is not loaded properly, as there is HTTPS link and the browser won’t load it. Clearing CSS cache helps just for a short time. Just until the cache stores the HTTPS link again.
@bradvin: would it be possible to disable CSS cache or force to store HTTP links only?
