I have WP Super Cache running with no problem on another site hosted identically.
The cache status message option is enabled in Debug.
The test cache on my problem site (http://bracedesign.co.uk) is showing Time stamps differ or were not found.
I have checked the following against the working site:
.htaccess in root and cache folder
WPCACHEHOME defined with correct path in wp-config.php
advanced-cache.php and wp-cache-config.php appear in wp-content folder
supercache folder contains site data
The meta folder only contains two small .meta files and I don't know if this correct.
I've tried deactivating the plugin and deleting advanced-cache.php and then re-activating the plugin.
I am running Cloudflare with the site (with Cloudflare's plugin) but they say this shouldn't interfere with Super Cache.
Can anyone please suggest something else I can try?