Black square when I use Graphics.DrawTexture?

Hi! I have a problem when I use Graphics.DrawTexture(). I need this function to crop a PNG image, and show that image on screen. The size to crop is increasing with the iterations. I have two calls to this methods, one from 0,0 of the screen, and the another one from Camera.pixelWidth. So, the first call makes me appear on screen a black square and I don’t know where I amb drawing it. The second call works fine, and if I comment it, the problem persists. I’m sure that the problem is in the first call, but I don’t know why…

Here’s my code:

public void OnGUI(){
		if(pPantalla <= 0.5f)pPantalla += 0.001f;
		Rect pantalla = new Rect(0.0f, 0.0f, (Camera.mainCamera.pixelWidth)*pPantalla, Camera.mainCamera.pixelHeight);
		Rect percentatge1 = new Rect(1.0f-pPantalla, 0.0f, pPantalla, 1.0f);
		Graphics.DrawTexture(pantalla, textura, percentatge1,0,0,0,0,null);
		Rect pantalla2 = new Rect(Camera.mainCamera.pixelWidth-(Camera.mainCamera.pixelWidth*pPantalla), 0.0f, (Camera.mainCamera.pixelWidth)*pPantalla, Camera.mainCamera.pixelHeight);
		Rect percentatge = new Rect(0.0f, 0.0f, pPantalla, 1.0f);
		Graphics.DrawTexture(pantalla2, textura, percentatge,0,0,0,0,null);


And here is an image from the problem. If you can see the upper-right black rectangle…that’s my problem.

Thanks in advance!!

SOLVED: the problematic zone was near the 0,X (a thin rectangle on the left part of the screen). I supposed that it was a conflictive zone (positive and negative values in the world position, etc.) and I turned 180º the main camera, and now it does the work perfectly.