DiscJuggler on-the-fly and LG GCE-8520

When I burn on the fly it only goes at 16x with my LG 52x24x52x.

Although I burn it with the option to save the entire content in a temporary file, the speed is still 16x. However burning an image went ok at 52x.

Do I do something wrong?

Thanks in advance.

The problem is solved by attaching the devices to different IDE channels.