I am contributor to the Closed Question module, and received this bug report:

I'm having compatibility issues with Closed Question 7.x-2.2 (...) and Entity Cache (...)

When Entity Cache is enabled, the fields/body of my Closed Question nodes are often not rendered at all (the Submit and Reset buttons are rendered, however), (...)

Disabling Entity Cache resolves the issue. Clearing all site caches or re-saving the node also resolves the issue, but only temporarily.

http://drupal.org/node/1415100#comment-7283714

I have no clue where to start looking in my code. Does anyone here has a clue what could cause this bug?