I have a mod that's ported to FML from ModLoader.  Everything's working okay as of now except that when I use both ModLoader.addName and LanguageRegistry.addName, all items in the mod resort to being named the last one applied.

 

public class mod_Tools extends BaseMod
{
  public static lx texToolSword;
  public static lx texToolPickaxe;
  public static lx texToolHelmet;
  public static lx texToolPlate;
  //Ignore the addTool/ArmorMaterial stuff.
  public static final wk ToolSword = new ItemToolSword(160, LinkseyiForgeAdapter.addToolMaterial("Rod", 1, 64, 7.0F, 2, 2)).c("ToolSword");
  public static final wk ToolPickaxe = new ItemToolPickaxe(161, LinkseyiForgeAdapter.addToolMaterial("Rod", 1, 64, 7.0F, 2, 2)).c("ToolPickaxe");
  public static final wk ToolHelmet = new ItemToolHelmet(162, LinkseyiForgeAdapter.addArmorMaterial("DiamondTwo", 7, new int[] { 6, 6, 7, 6 }, , ModLoader.addArmor("DiamondTwo"), 0).c("ToolHelmet");
  public static final wk ToolPlate = new ItemToolPlate(163, LinkseyiForgeAdapter.addArmorMaterial("DiamondTwo", 7, new int[] { 6, 6, 7, 6 }, , ModLoader.addArmor("DiamondTwo"), 1).c("ToolPlate");

  public void load()
  {
    ModLoader.addName(ToolSword, "Tool Sword");
    ModLoader.addName(ToolPickaxe, "Tool Pickaxe");
    ModLoader.addName(ToolHelmet, "Tool Helmet");
    ModLoader.addName(ToolPlate, "Tool Plate");
  }
}

 

In this case all items end up being named "Tool Plate".

This should be moved to Modder Support.

And you should be using just LanguageRegistry.