Yay, three cheers for Jeff. Reverting to the stock libibverbs package (still at 1.0-4 for the version of Ubuntu I'm running at work as I haven't upgraded to last week's Ubuntu 7.10 release) and rebuilding the Open MPI 1.2.4 deb packages under it fixes the openib error message issue.
So even for the Open MPI 1.2.* series, the 'filter after dlopen' works perfectly fine, and the mca parameter setting, either from command-line or config file, works as expected and suppressed openib messages and loading. Good. I apologise for the line noise. This arose from when I used this machine for early tests before we got the Debian packages for Open MPI into shape, and I had simply forgotten that I had a modified libibverbs on one box. I guess the upshot is that I should use a pbuilder environment at work too... Thanks, Dirk -- Three out of two people have difficulties with fractions.