If you think there is a bug in "msm", the mainatiner is probably
interested in fixing it.
So it would be a good idea to ask him (the maintainer) kindly if there
is a problem and you should provide a reproducible example that shows
the error or even better provide a suggestion fo a fix.
Telling the world that you *think* there is a bug in some package
without any further information (such as an reproducible example) is
certainly not the way to go!
You could also say the sofware product X returns incorrect results. This
is probably true for most software products I know, including R.