R Batch proc.time doMPI

I've been running doMPI jobs on a slurm cluster with R BATCH foo.R  and I'm used to getting a final line
in foo.Rout with the output of proc.time() as promised by ?BATCH.  At least this was the way things worked
with R BATCH on my multicore desktop.  But I don't get any proc.time() output from the cluster runs
and wondered why not, or whether I should be doing something other than 

save.image()
closeCluster(cl)
mpi.quit()


as the job finishes.  Thanks in advance.

Roger