PHP-FPM: zend_mm_heap corrupted

Hello together, I am using PHP-5.5.10 (latest Version from Dotdeb) running via the PHP-FPM on Debian Wheezy. I have the problem that a lot of requests return as an internal server error and the fpm-log says: child xxx said into stderr: "zend_mm_heap corrupted". This only happens to me if I restore a large object structure which has been serialized and stored via APCu. It seems to be happening on specific pages only but not on every requrest. So far I could not simplify my pages and create a reproducible example for it. I use traits (which I mention as there was an error fixed which caused zend_mm_heap and which involved traits). I would appreciate any help in finding and fixing this problem. Greets, Dennis