Remote stopped working with TV, okay with LG HDD DVD Recorder

My LG HDD DVD Recorder remote was working fine with my LG LCD TV until yesterday. Suddenly today, it stopped supporting the TV, however, it is still operating the recorder fine as before. Any suggestions what to do???
Another Remote for TV doesn't work with TV either.
I was making some changes to TV when remotes stopped working.
Perhaps TV needs to be set to default but I don't know how to do that.