Anyone know how to solve this?

Hey,

I have a Platinum Cube, I am running PSUL with GCoS1.4.

I have Nero and made some backups.
My nero locks my write speed at 4X. I have tried two disks; Verbatim Digital Movie DVD-R mini, and Optodisc R004. I burned two exact copies of POP2-WW, MarioParty5. Only the Verbatim disks work. I have read on this forum that Optodiscs have been tested and are working. Am I doing something wrong?

I have tweeked my laser trying different settings starting from 230 to 150. Nothing seems to work.

If anyone knows what i'm doing wrong, or how to slow nero ( if it makes a difference), or simply has any ideas, please let me know.