Although I have seen quite a bit of discussion about this error message (The selected RPI failed to initialize during MPI_INIT message), I didn't see anything that addresses my situation.

I am running on a Mac Intel dual-core laptop.  I successfully installed LAM MPI and have been running it for a few weeks.  Here is the info from lamboot -V:

LAM 7.1.3/MPI 2 C++/ROMIO - Indiana University

        Arch:           i386-apple-darwin8.8.2
        Prefix:         /usr/local
        Configured by:  maherou
        Configured on:  Tue Mar 13 19:48:11 CDT 2007
        Configure host: herouxmac.local
        SSI rpi:        crtcp lamd sysv tcp usysv

However, just today programs that I compiled and ran correctly last week no longer work.  I get the following message:

-----------------------------------------------------------------
The selected RPI failed to initialize during MPI_INIT.  This is a
fatal error; I must abort.

This occurred on host herouxmac (n0).
The PID of failed process was 25633 (MPI_COMM_WORLD rank: 0)
-----------------------------------------------------------------

I have rebooted my machine to make sure that there weren't problems with system resources.

The only things I can say have changed are that I installed some new software yesterday, in particular Matlab.

I am able to run my codes if I specify the RPI, e.g., "mpirun -ssi rpi crtcp ..." .  It appears that modes crtcp, lamd and tcp work, but sysv and usysv do not.

This is not a critical problem for me now, since I can run my programs, but I am puzzled about how the behavior changed.

Mike