Have you made any changes to the programming at all? Or any other changes in equipment? If not, I would lean towards possibly a bad remote. The fact you have a second remote working perfectly directs me towards the remote's RF board going bad. It's not all that common, but can happen. If you have programmed anything at all, and even if you haven't, just double check that the RF is set properly still on the 980 and the 260 is set to the proper RF ID in the 980 program.