I've modified the source code and traced into it.

error occured at here in the file multicpu.cpp

DWORD __declspec(naked) mp_GetNumberOfCPUs()
{
__asm
{
pushad
int 3
mov ecx, 128
mov edi, offset HalInitializeProcessor
mov edi, [edi]
cld

search_some_bytes:
mov al, 89h
repne scasb <====!!!! error ocurred here
jnz short return_default
..........
retn
}
}

cause my PC has only one CPU. so, i modified this function like this

DWORD __declspec(naked) mp_GetNumberOfCPUs()
{
__asm{
xor eax,eax
inc eax
retn
}
}

after rebuild, IceExt works fine.