OK, but you need to understand that a "segmentation fault" is a serious bug - in effect, a system crash. This should never, ever happen, with PHP or any other scripting language. That it does means that there is a very low-level bug in PHP, or perhaps a conflict between this and another part of your system (database module etc.).
So, I recommend to you again, upgrade your version of PHP. Alternatively, disable any optimisers or accelerators you might be using.