Front pages on multisite not being cached

[khromov]

I have the above issue with WP-FFPC.

Stack: Apache / mod_php / PHP 5.3 / APC WordPress MultiSite with subdomain mapping. Network Activated WP-FFPC.

Issue: The front page of all sites in the network is not cached. The front page of the first blog is cached however.

Example: site.com/ - cached site.com/test - cached subsite.site.com/ - not cached subsite.site.com/test - cached

Any ideas why this is happening? I have not enabled any cache exceptions.