Nexus Mod Manager 0.56.2 works quite well, and is quite stable on every system I've ran it on, Nexus Mod Manager 0.60+ has been crap, it doesn't place the meshes and textures for the mods in the game folder (Skyrim and possibly others). 0.56.2 just installs the mod, and works
Maybe adding new games to the 0.56.2 code, and improving Nexus Mod Manager would have given it a 1.0 release