Texture.ReadPixels and iOS Problems

I seem to be having an issue when it comes to reading the display buffer of iOS6 devices. After a call to readpixels, the texture is just black. It works fine in the editor and on my android devices, but on iOS6 devices it doesn't work. I found some documentation that said that apple made some display buffer changes and that glReadPixels now functions differently. I tried a work around that involved changing a boolean in xcode and it is as follows...

 extern "C" void InitEAGLLayer(void* eaglLayer, bool use32bitColor)
 {
     CAEAGLLayer* layer = (CAEAGLLayer*)eaglLayer;
 
     const NSString* colorFormat = use32bitColor ? kEAGLColorFormatRGBA8 : kEAGLColorFormatRGB565;
 
     layer.opaque = YES;
     layer.drawableProperties =  [NSDictionary dictionaryWithObjectsAndKeys:
                                     [NSNumber numberWithBool:YES], kEAGLDrawablePropertyRetainedBacking,
                                     colorFormat, kEAGLDrawablePropertyColorFormat,
                                     nil
                                 ];
 }

that has not solved the problem for me. Its worth noting that all of my calls to the texture happen in OnPostRender. My camera calls a function to perform the texture manipulation.

EDIT: For clarification the function below is located in the main camera, while the function it calls is in a script used to create the gui

 function OnPostRender () {
 
 if(guiObj.GetComponent(TestGui).grab)
     guiObj.GetComponent(TestGui).OnPostRender();
 
 }

If anyone has any experience with an issue like this, some help would be greatly appreciated. It's quite frustrating that the code works on all devices but my iOS ones -_-

I am using unity 3.5.7f6