Sound played on dedicated test server but not in modded dedicated server

Hi, I have this code:

public abstract class BaseWeapon extends ItemSword {

public BaseWeapon(ToolMaterial material) {
	super(material);
}

@Override
public boolean onLeftClickEntity(ItemStack stack, EntityPlayer player,
		Entity entity) {

	if (!entity.isDead) {

		player.worldObj.playSoundAtEntity(player, Reference.MOD_ID + ":"
				+ this.getUnlocalizedName().substring(5) + "_hit", 1.0f,
				1.0f);
	}

	return super.onLeftClickEntity(stack, player, entity);
}
}

If i run a test server with no mods and connect to it, I hear the sounds playing, but when I use my normal minecraft client/server wich has a lot of mods, the sounds are no longer heard (or played?).

Is this a known thing or do you have any suggestion as how to resolve it other than try removing mods until i find the culprit?

This is a list of my mods:

• 
  1.8
  animalsplus-1.3.jar
  antiqueatlas-4.0.1a-1.7.2.jar
  BackTools-5.1.0.jar
  BaseMetals-1.4.0.jar
  Chameleon-1.8-0.1.0.jar
  CodeChickenCore-1.8-1.0.5.34-universal.jar
  CrafableHorseArmour 1.2.jar
  decorationmegapack-1.18-1.8-1446.jar
  ExpTranslation-1.0.0-1.8.7.jar
  Fire's Clay Spawn 2.1.2.0.jar
  iChunUtil-5.4.0.jar
  justbackpacks-mc1.8-1.0.jar
  LunatriusCore-1.8-1.1.2.28-universal.jar
  MobAmputation-5.0.0.jar
  MoreEnchantments-1.8-1.3.2.1.jar
  Morpheus-1.8-2.0.41.jar
  MouseTweaks-2.5.0-mc1.8.jar
  MrCrayfishFurnitureModv3.4.8-build1(1..jar
  NotEnoughItems-1.8-1.0.5.82-universal.jar
  oldguns-1.3.0_x32.jar
  pablismod-1.0.jar
  parachutemod-1.8.0-3.1.2-96.jar
  redstonepaste-mc1.8-1.7.1.jar
  SmeltCycle-2.0.jar
  StalkerCreepers-1.8.jar
  StorageDrawers-1.8-2.1.8.jar
  [1.8] ChickenShed (v1.2.0).jar
  [1.8]ArmorStatusHUD-client-1.29.jar
  [1.8]bspkrsCore-universal-7.01.jar
  [1.8]DirectionHUD-client-1.24.jar