Date: Mon, 12 Apr 2010 10:17:11 -0600
From: "Belcourt, Kenneth" <kbelco@sandia.gov>

You could try to edit mpi.jam around line 221 like this:

    if $(otherflags) {
       for unknown in $(unknown-features)
       {
         result += "$(unknown)$(otherflags:J= )" ;
       }
    }