Intel MPI ABI compatibility for symmetric execution (KNC) [updated]

Dear experts,

I noticed that my program under symmetric execution would crash if

• host code is compiled by icpc and uses MPICH-2 implementation by setting LD_LIBRARY_PATH at runtime
• KNC code is compiled by icpc and uses Intel MPI implementation

But it would be fine if

• host code is compiled by g++ and uses Intel MPI implementation
• KNC code is compiled by icpc and uses Intel MPI implementation

But doesn't this ABI compatibility initiative guarantee that both cases shall work fine? Could you give me some insight into this problem? I appreciate your help.