I've recently upgraded form 0.9.2.3 to the latest (0.9.2.9) and have run into loads of trouble.
The solutions is a WordPress Mutlisite solution with two sites. In previous version we used the plugin was activade on the individual sites, now it's only posible to network activate it. I don't know if that has anything with the problem though.
Well to the problem!
These problems are mainly about page cache, since we didn't get so far to activate the other caching options.
1. We are using Memcached servers to store the page cache, and with everything configures, the cache isn't purged when updating/publishing pages, hence the changes aren't visible.
2. The purge all caches option, seems to only purge now and then and the individual cache options "empty cache" doesn't seem to do anything.
3. Purging cache from network admin, doesn't affect the sites cache.
4. Also after a while, pages start to go completely blank and I will have to forcedly purge the entire cache (both with and without Cache Warming configured).
We are using WPML to add additional languages on the site, and the .4 mostly occur on the secondary language which is reachable through ex /en/
We are using domainmapping to map domains to the sites in the network, when going to the page using the main domain with www. it works fine, but entering the site without www. renders a blank page.
All this worked flawlessly in 0.9.2.3.