I've run into an issue with W3 Total Cache's page cache system. It's caching the mobile version of my site, then subsequently serving the cached mobile page to users that visit the main page.
I'm not sure how to reproduce it. Happens sporadicly. In order to fix it I have to restart PHP. All cache settings are set to use the XCache opcode.
If it helps, here's a little background on my setup. Mobile users are directed to http://m.domain.com. Regular browsers can access this page as well. MobilePress changes the theme depending on two conditions. If the user visits that URL -- and also if their user agent matches that of a known mobile browser.
A simple solution (in my eyes) would be to completely block caching on m.domain.com. Is there any way I can do this?
For the time being I have disabled page caching and the issue has yet to surface again.