Yes, in the French version he's called "Dark Vador" which, when you undestand English, makes it sound anyway like the "Dark Father", which makes much sense after EP3.

I've never understood why in the English version it's "Darth" ... does it mean anything actually ?

Actually, as I'm able to watch both versions, I think that the voices in French in EP4-5-6 make them greater than the original version ... the characters are more "sympatic" and "catchy" in the French version, especially Han Solo (edit: and Yoda). Although in EP4 French version there's a mistake because the say the "Millenium Condor" instead of "Faucon (Falcon) Millenium".
I haven't seen EP2-3 in French.