I would try that, but the 2600 doesn't have some of the required codes. I did try the RX-V1700 codes (very similar and listed on the Yamaha IR sheets together), but no luck there either.
I have tried to generate the HEX codes and program that way; but that fails too. I guess the Yamaha Codes I have are either wrong, or there is a difference between the codes for the receivers in different countries. Right now it seems to be the latter.