Hacking unable to read disk

[tbe0dip]

Hi:

I have Wii with version 3.3 U, I follow up porcedure with http://www.iol.ie/~taz/wii/WiiHowToGamma.html step by step.
after installation I insert disk which i copied ISO (include brickpatcher) by imgburn on DVD-R (TDK, SONY, RIDATA) with 2.4X speed but every time I get message that unable to read disk.

am I missing some step? I really appreciate reply on this

Thank YOu