[gregfielding]

I though I found the solution, reading these threads…maybe it’s an issue with recognizing content types?

https://wordpress.org/support/topic/batcache-ignores-content-type-header-sends-everything-as-texthtml?replies=3

http://maisonbisson.com/blog/post/13773/fixing-batcache-to-send-the-correct-content-type-header/

But this fix didn’t work – just took the memcached served offline.