TerrRender.cc multitexture problem

Hi,

I'm trying to use a new texture on top of the terrain textures(base, lightmap, etc...) to add some effects.

When I use any of the OpenGL textures below GL_TEXTURE4_ARB it works fine.
These textures appears to already been used by the terrain:
GL_TEXTURE0_ARB - Base texture
GL_TEXTURE1_ARB - Lightmap
GL_TEXTURE2_ARB - Fog
GL_TEXTURE3_ARB - Not sure

So I'm trying to use the GL_TEXTURE4_ARB but when I use this one nothing happens.

Any ideas???

Below is my code:

if(mXFIndexCount)
{
	if(blendedlighting)
	{
        glActiveTextureARB(GL_TEXTURE1_ARB);
        glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, mCurrentBlock->lightMapTexture.getGLName());
		...
	}

	PROFILE_START(TerrainRenderBind);
	glBindTexture(GL_TEXTURE_2D, walk->handle.getGLName());
	doTexGens(sgTexGenS, sgTexGenT);
	PROFILE_END();

	// -----------------------------------------------------------------------------
	PROFILE_START(TerrainRenderCaustics);


	//
	// WORKS VERY WELL WITH GL_TEXTURE1_ARB
	//

	glActiveTextureARB(GL_TEXTURE4_ARB);
	glClientActiveTextureARB(GL_TEXTURE4_ARB);
	glEnable(GL_TEXTURE_2D);
	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, GL_MODULATE);

	glEnable(GL_TEXTURE_GEN_S);
	glEnable(GL_TEXTURE_GEN_T);
	glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
	glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);

	F32 offset = 10.0 / (F32(mCurrentBlock->getSquareSize() * mCurrentBlock->mCausticsSize) * TerrainBlock::BlockSize);
	glTexGenfv(GL_S, GL_OBJECT_PLANE, Point4F(offset, 0, 0, 0));
	glTexGenfv(GL_T, GL_OBJECT_PLANE, Point4F(0, offset, 0, 0));

	// Timer
	static U32 lastTime = Platform::getRealMilliseconds();
	static U32 elapsedTime = 0;
	static int currentFrame = 0;

	U32 currentTime = Platform::getRealMilliseconds();
	elapsedTime = currentTime - lastTime;

	if (mCurrentBlock->mCausticsTextureHandle[currentFrame])
		glBindTexture(GL_TEXTURE_2D, mCurrentBlock->mCausticsTextureHandle[currentFrame].getGLName());

	// Update frame
	if (elapsedTime > 100 * (1.0/mCurrentBlock->mCausticsSpeed) )
	{
		currentFrame++;
		if (currentFrame == TerrainBlock::NumCausticsTextures ||
			!mCurrentBlock->mCausticsTextureHandle[currentFrame])
			currentFrame = 0;

		lastTime = currentTime;
		elapsedTime = 0;
	}

	PROFILE_END();
	// -----------------------------------------------------------------------------

	PROFILE_START(TerrainRenderSetVertexBuffer);

	if(vertexBuffer)
		glSetVertexBufferEXT(block->mVertexBuffer);
	if(lockArrays)
		glLockArraysEXT(0, mXFPointCount);
	// lock the array
	PROFILE_END();
	PROFILE_START(TerrainRenderXFRender);
	renderXFCache();
	PROFILE_END();

	// Redo
	glDisable(GL_TEXTURE_2D);
	glDisable(GL_TEXTURE_GEN_S);
	glDisable(GL_TEXTURE_GEN_T);
	//glClientActiveTextureARB(GL_TEXTURE0_ARB);
	glActiveTextureARB(GL_TEXTURE0_ARB);

	...
	...
}

Thanks!! =)