Problem with generating blocks

package net.minecraft.src;

import java.util.Random;

public class mod_ElementalOres extends BaseMod
{


public static final Block elementaliron = (new BlockElementalIronblock(150,ModLoader.addOverride("/terrain.png", "/mods/elementaliron.png" ) )).setHardness(1F).setStepSound(Block.soundStoneFootstep).setBlockName("elementalironblock").setLightValue(0.5F);
public static final Block elementaldiamond = (new BlockElementalDiamondblock(151,ModLoader.addOverride("/terrain.png", "/mods/elementaldiamond.png" ) )).setHardness(1F).setStepSound(Block.soundStoneFootstep).setBlockName("elementaldiamondblock").setLightValue(0.75F);

public void load()
{
ModLoader.registerBlock(elementaliron);
ModLoader.addName(elementaliron, "Elemental Iron ore");
ModLoader.registerBlock(elementaldiamond);
ModLoader.addName(elementaldiamond, "Elemental Diamond ore");

}

public void generateSurface(World world, Random random, int i, int j)
{

for(int i4 = 0; i4 < 20; i4++)
{
int j7 = i + random.nextInt(16);
int k10 = random.nextInt(30);
int j13 = j + random.nextInt(16);
(new WorldGenMinable(mod_ElementalOres.elementaliron.blockID, 4)).generate(world, random, j7, k10, j13);
}

}

public void generateSurface(World world, Random random, int i, int j)
{

for(int i4 = 0; i4 < 20; i4++)
{
int j7 = i + random.nextInt(16);
int k10 = random.nextInt(7);
int j13 = j + random.nextInt(16);
(new WorldGenMinable(mod_ElementalOres.elementaldiamond.blockID, 8)).generate(world, random, j7, k10, j13);
}

}




public String getVersion()
{
return("Elemental Ores V1");
}


}