I've added the item properly, I believe, but it just won't show up in any tab I've made or the default ones.

 

Main Class:

 

public class Fallout
{
public static final String MODID = "fallout";
public static final String VERSION = "a1.0";

@Instance("fallout")
public static Fallout instance;

@SidedProxy(clientSide="blfngl.fallout.proxy.ClientProxy", serverSide="blfngl.fallout.proxy.CommonProxy")
public static CommonProxy proxy;
public static ClientProxy cproxy;

        public static CreativeTabs TabFalloutParts = new TabFalloutParts(CreativeTabs.getNextID(), "TabFalloutParts");

public static Item cellEnergy;

@EventHandler
public void load(FMLInitializationEvent event)
{
	cellEnergy = new FalloutItem().setUnlocalizedName("cellEnergy").setCreativeTab(CreativeTabs.tabTools);
	GameRegistry.registerItem(cellEnergy, "cellEnergy");
	//ItemHandler.init();
}
}

 

Item Class:

 

package blfngl.fallout.item;

import java.util.List;

import net.minecraft.client.renderer.texture.IIconRegister;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import blfngl.fallout.Fallout;
import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;

public class FalloutItem extends Item
{
public FalloutItem()
{
	super();
	setHasSubtypes(true);
	setCreativeTab(Fallout.TabFalloutParts);
}

@Override
public void registerIcons(IIconRegister iconRegister)
{
	itemIcon = iconRegister.registerIcon("fallout:" + this.getUnlocalizedName().substring(this.getUnlocalizedName().indexOf(".") + 1));
}
}

 

 

Thanks for your time

You did everything in FMLInitializationEvent.

 

Starting - 1.7, Forge now loads things with

FMLPreInitializationEvent

 

In other words change init(load) to preInit.