LG4120b can't write to TDK 8x DVD+R @ 12x

this is the ricohjpnr02 dvd+r media. My drive has fw A111 rpc1

I’ve tried connecting it to both my mobo southbridge (nforce2) and Silicon Imsge 0680A RAID card and it can only write to my discs @ 8x.

it is set as master on its own on a channel.

what’s wrong? argh :a