MPICH2 Rmpi and doSNOW

Hi

I have managed to install MPICH2 and Rmpi on my Windows 7 machine. I can
also run the following code

library(Rmpi)
mpi.spawn.Rslaves()

4 slaves are spawned successfully. 0 failed.
master (rank 0, comm 1) of size 5 is running on: MyMaster 
slave1 (rank 1, comm 1) of size 5 is running on: MyMaster 
slave2 (rank 2, comm 1) of size 5 is running on: MyMaster 
slave3 (rank 3, comm 1) of size 5 is running on: MyMaster 
slave4 (rank 4, comm 1) of size 5 is running on: MyMaster

mpichhosts()

master      slave1      slave2      slave3      slave4 
"localhost" "localhost" "localhost" "localhost" "localhost"

mpi.universe.size()

[1] 4

mpi.close.Rslaves()

[1] 1

library(doSNOW)

But every time I try to set up a cluster via

cluster <- makeCluster(4, type = "MPI")

My computer hangs up and I have to close the R session.

Any advice how I get this running?
Thanks in advance

sessionInfo()

R version 3.0.1 (2013-05-16)
Platform: x86_64-w64-mingw32/x64 (64-bit)