Graphics.DrawTexture not working after changing quality settings

Hello, I've got a rather strange problem. I have a pause menu set up, w$$anonymous$$ch takes a screenshot of the scene (using SetPixel, since I only have Unity Indie), and then draws it to the screen with a shader using Grap$$anonymous$$cs.DrawTexture. In my pause menu, I have an option to change the grap$$anonymous$$cs settings on the game. On doing so, however, the call to Grap$$anonymous$$cs.DrawTexture suddenly stops working. If I draw the texture using GUI.DrawTexture, then it works perfectly well (except, obviously, without the shader, w$$anonymous$$ch is necessary for the effect), but Grap$$anonymous$$cs.DrawTexture doesn't, until I close the pause menu and create a new object. I'm wondering why t$$anonymous$$s is, and if there is any way I can force the Grap$$anonymous$$cs object to update, or refresh, in order to render correctly.