When looking at /usr/lib/openoffice/program, I found that many files in there were owned by user and group "portage". This is clearly a bug. I think that portage should check for this when installing (and/or creating a binary package). Possibly with an override for cases when files are legitimately owned by the portage user.
reinstall the package. portage already forces file perms to root if they're portage group...
Ok, I didn't see that. I guess that would fix the portage group issues.