When I first installed MySQL 5.6.11 on Mountain Lion it worked fine for a week. The only issue was I couldn’t get the service to automatically start from boot.
Strangely a week later it started recursively crashing, the only way to stop it was a kill -9 on the mysqld process.
At first I thought this might be due to running the database with a Postgres installation running as well, something that gets setup when you install Daylite, the excellent CRM package. But this was not the cause.
The only way I found to fix it was uninstalling the 64 bit version and installing the 32 bit. I had read something earlier describing this issue.