FIM Syncronisation service 2010 R2 sp1 stopped-server on ECMA

Hello

I have an aleatory exception : stopped-server on all of my FIM sync service 2010 R2 sp1.

I don't have this error on FIM sync service 2010 

This exception occurs on different ECMA and different execution profile (Import, Synchro).

With restarting the service, the excption doesn't appear anymore but for an unknow reason it reappears:

in the event viewer I have thos kind of error :

Faulting application name: miiserver.exe, version: 4.1.3419.0, time stamp: 0x511d9c79
Faulting module name: clr.dll, version: 4.0.30319.17929, time stamp: 0x4ffa59b1
Exception code: 0xc0000005
Fault offset: 0x00000000004e5900
Faulting process id: 0xf8c
Faulting application start time: 0x01cefcaa20d1eda1
Faulting application path: C:\Program Files\Microsoft Forefront Identity Manager\2010\Synchronization Service\Bin\miiserver.exe
Faulting module path: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll
Report Id: 9f8b2bbb-689d-11e3-b2ce-000a30ffa3a5

OR 

Faulting application name: miiserver.exe, version: 4.1.3419.0, time stamp: 0x511d9c79
Faulting module name: ntdll.dll, version: 6.1.7601.17514, time stamp: 0x4ce7c8f9
Exception code: 0xc0000005
Fault offset: 0x0000000000018e3d
Faulting process id: 0xed4
Faulting application start time: 0x01cefc16c915f872
Faulting application path: C:\Program Files\Microsoft Forefront Identity Manager\2010\Synchronization Service\Bin\miiserver.exe
Faulting module path: C:\Windows\SYSTEM32\ntdll.dll
Report Id: f00f29a1-6895-11e3-b2ce-000a30ffa3a5

Thanks for your help.