DynamicTexture in fxRenderObject : Error on Exit

Hi

I attempted this to find out more about the DynamicTexture.
In the fxRenderObject::onAdd, I added

mTestTex = new DynamicTexture();

Right in the fxRenderObject::renderObject

....
mTestTex->setUpdateRect(viewport);
...
...
glBindTexture( GL_TEXTURE_2D, mTestTex->getTextureHandle().getGLName() );
...
...
mTestTex->update();

dynamicTexture class was able to update from the viewport and render perfectly fine onto the fxRenderObject.

But when I exit the entire game, I got this error
[bold]Error, some object didn't unregister it's texture event callback function[/bold]

I tried to use unregisterForScreenUpdates in the deconstructor but that doesn't solved the problem.
Any help and advise will be appreciated.