I've had this issue for a while now and have never been able to get it solved - even after chatting in Slack about it with some people. Basically whenever I go to update an entry, Craft hangs and locks up Apache. It times out in about 5 minutes or if I manually restart Apache, things go back to normal. The entry is updated after the server restarts so it appears that the database write is successful.
It's becoming a huge problem as I'm finishing up a site for a client and they're needing to put content in. I'm running this on a Google VM and have tried installing it on a fresh server with no luck. I'm running Ubuntu 14.0.3. I'm running other Craft sites on Google and have no issues.
I tried a few steps a while back (I can't remember what exactly), I believe I increased a couple parameters in PHP.ini but I honestly can't remember. I used to be getting the zend_mm_heap_corrupted error but that's gone away now from my Apache error log.
Any help is appreciated. It's getting sort of urgent at this point since my deadline is approaching and entries need to be worked on.
My Apache version is 2.4.7 if that makes any difference.