Matt,
You are correct, I can get all of the codes from URC other then the Discrete On/Off to work properly. I have the Remote Switch on the back of the DV-4001 set to EXT for External. I am using the MRF-350 from URC and I am sending the codes via RF and then I am directly connecting the MRF-350 to the DV-4001 and I cannot get the codes from above to work. Yes, I have tried to paste them into the Universal Browser but I still cannot get them to work. This week I will try to change the cable from the MRF-350 to the DV-4001. I will also try to just use the codes via. IR instead of RF. Ill post my results.
Any other suggestions? Are you directly connecting your MRF unit to the back of the Marantz DVD player? If so, what do you have the Remote Switch set to on the back of the Marantz DVD player.....