slow MPI on laptop

[William R.Pearson]

Your problem almost certainly has to do with the lack of a DNS server
when your ethernet is not plugged in.

I have seen the same problem under OSX.

You need to figure out a way to convince your operating system
to determine quickly (without timing out) that  localhost is on your 
machine
when it is not on a network.

I have found that this can be difficult.

Bill Pearson