Oops I can't proof read my messages:

> However because the openmpi-devel 1.1.1 isn't removed when upgrading the 
> alternatives it added arn't removed
> and being at the same priority as the new ones don't get zapped so 
> /etc/alternatives/mpicc (etc) still point at
> /usr/bin/opal_wrapper-32 which no lomnger exists...

I meant to say something more like:

...
However upgrading openmpi-devel from 1.1.1 to 1.2.3 doesn't count as 
'removal' of 1.1.1.  Therefore the alternatives links made by installing 
openmpi-devel 1.1.1 arn't removed by the upgrade and as the priorities are 
the same the links don't get updated and /etc/alternatives/mpicc (etc) 
still point at /usr/bin/opal_wrapper-32 which no lomnger exists...
...

Hopefully that is a little bit clearer...

  -- Jon