[MPICH] Urgent help with compiling

[Kevin C.]

I am getting a whole load of linkage errors when I compile:

/usr/lib/mpich/lib/libmpich++.a(comm.o)(.gnu.linkonce.t.__tfQ23MPI9Comm_Null+0x1d): 
In function `MPI::Comm_Null type_info function':
: undefined reference to `__rtti_user'

I am using the mpiCC (mpicxx) compiler to compile .cpp code. I am using 
normal C MPI function calls though.

My program compiled and ran fine on another machine. But not anymore on this 
new cluster I moved to.