I use 2 Dish Network receivers. A 522 DVR (PITA with the fracking RF tuner) and a 301 single receiver.
First, on the receiver you are changing the code on, get up the menu, settings, remote code section.
Second, grab the remote, press and hold the "SAT" button, and then a number from 2 to 9 (its set at 1 currently) this changes the remote code, and after this is done, use your USB-UIRT and re-learn the codes. For instance I have a 522 template using code "1" and a 301 template using code "6".
After changing the remote code, using the front panel arrows and "OK" button, change the remote code number to correspond with for the above example "6". That should be it, to test, exit out of the menu with the remote.
After that is done, depending on which tuner is called, the UIRT will fire the right set of codes, and your issue is resolved
Happy watching and Regards,
Seth