Im amazed the 850 is still a current model, only due to it being a Serial remote - I've owned one and programmed many of them and they are great remotes.
I sent an email to URC recently inquiring about their IRDB being updated for the 810 and got this response:
We appreciate you contacting Universal Remote Control, Inc and your continued patronage. Unfortunately we have not yet added the Denon 4311CI to the IR Database for the MX-810 however it should be updated soon. In the meantime we recommend using the codes for the 4310CI as most of the commands are the same and should be compatible. We hope this information is helpful and apologize for any inconvenience this may cause.
