When selecting one of the user groups in the security tab, i was getting an is_dir error in saphhire/core/i18n.php in the get_existing_translations(). The server is pretty well locked down, and was bailing when the method was looping over the ".." directory in the root.
I put this little hack in (there is probably a 'right' way to do this in php, but I don't know it)
$moduleDir = $baseDir . DIRECTORY_SEPARATOR . $module;
$langDir = $moduleDir . DIRECTORY_SEPARATOR . "lang";
if (substr ($moduleDir, -2) == ".." || substr ($langDir, -2) == "..")
which seemed to fix it...