Double layer problem on NEC 3550a

I have a stock 3550a with the standard 1.05 firmware. I’ve been able to burn double layer Ritek +R disks with no problem at 2.4x.

I recently got a batch of 4x Ritek -R disks and can’t burn the darn things. I keep getting an Illegal disk error in Nero (6 or verison 7) even if I try burning them at any speed. I’ve tried other burning software (IMGBurn, etc) with the same results.

The media code is RitekP01 and I assume the firmware needs an update to support it. Anyone know what version of the firmware supports this 4x double layer media?

TIA.

Firmware needs to be updated, of course.

Yes, though as far as I can tell 1.05 is the most recent firmware. Would you know of anything more recent?

Nope, then the Ritek -DL 4x are too new.

I would use Verbatim DL instead anyway.