Looks like the receiver has a discrete power on and off. Try the following to set the POWER OFF to Shift-POWER. Assuming you have device code 1254 set to AUX device key:

1. Press and release AUX
2. Press and hold SETUP until remote blinks twice
3. Type 994
4. Press and release SETUP
5. Type 64257
6. Press and release SETUP
7. Press and release POWER

Now, if you press and release SETUP and then press POWER, the device should turn off. If you don't like to Shifted-POWER key (really SETUP and POWER, SETUP key acts like SHIFT function to allow another key definition on these remotes), choose another key (like PIP On/Off on the bottom), follow the above step except don't do STEP 6 and press and release the chosen key for STEP 7.