Try assigning device code 1376 to the CBL device key:
1. Press CBL key
2. Press and hold SETUP until CBL blinks twice
3. Type 1376

It should blink twice. If it blinks long once, it could be one of two problems. One could be that CBL device is locked. To unlock it:

1. Press CBL key
2. Press and hold SETUP unit CBL binks twice
3. Type 982

If it blinks four times, now it's unlocked and you can do the above step to set to it to 1376. If it blinks twice, that means it was unlocked and now is locked, and you need to do the step above again to unlock it again. It also means that 1376 code is not present for some reason (possibly it was completely reset).

You could use device code CBL/0476, which is built in, but it will not have the DVR commands and you would have to use advanced codes to program that in manually. I would just get a new one (that's has the correct code), but if you want to program them in instead of bothering to go back to the cable company, I can give you the list of codes for the missing commands and how to program them in.