Suddenly server crash, too many lsphp4 created

[fastproxy]

Suddenly, I got alot of these error in /var/log/messages

Jan 10 15:47:08 myserver kernel: lsphp4[3480] general protection rip:55f47e rsp:7fffc370ce60 error:0
Jan 10 15:48:03 myserver kernel: lsphp4[3592] general protection rip:55f47e rsp:7ffff37ebf40 error:0
Jan 10 15:48:20 myserver kernel: lsphp4[3580]: segfault at 0000000000000011 rip 000000000055f47e rsp 00007fff62bb9310 error 4
Jan 10 15:49:03 myserver kernel: lsphp4[3670] general protection rip:55f47e rsp:7fffd4f496a0 error:0

Also this message with logwatch:

--------------------- Kernel Begin ------------------------
WARNING:  General Protection Faults in these executables
    lsphp4 :  203 Time(s)
---------------------- Kernel End -------------------------

The server crashed very frequent and there are many lsphp4 process filled up very fast. I have to setup a manualy cronjob to kill those process every minute or else the server load will goes above 100, and the waitQ is high then server became dead.
I checked and there is no sign of DDOS or DOS.

What is the problem?

I am running CentOS 64 bit, 2x Quad-Core AMD Opteron 2344 HE, 16GB of RAM