I'm under Windows Seven, if this change anything.
I have replaced the altplanetnames.txt file in the Runtimedata directory by alternate names, and this does not change anything, I'm still with the random vanilla names. Can somebody tell me if it happened to him?
I can even delete the file, and I still get the names... And I have only one copy of the game on my HD, in case you wonder if I'm not editing a game and using a shortcut on another copy of it, nope
So? Weird, no?