The language files included in the WP-Members 2.7.5 release evidently were only in the tagged release, and not the svn trunk (which is where the automatic update is coming from).
So… if you updated prior to 10:40 AM US Central time, 6/14/2012 and you need specific language files that were included in the update, you should redownload (or at least check the svn repository).
If you have sent me a translation that was missed, I apologize – please contact me to resend. Everything that is included in this release is what I currently have.
If you are able to update one of the languages that is missing some strings, please let me know so we can include an updated version with the download.
If you are a user of the plugin that relies on these translations, I thank you for your patience. I am doing my best to get them updated and keep them updated so we can include them in the download package for everyone.