Bummer! I grew up with the Rockford Files..
Does anybody remember about '75-'76 or so they replaced The Rockford Files with a similar show that Garner made appearances in (as a mentor) called "Richie Brockelman-Private Eye starring Dennis Dugan?" It was short-lived.. While it wasn't bad, it just wasn't as popular and after a few weeks they brought back The Rockford Files from limbo-or the different (non-primetime) slot they had put it in.
(Actually I just checked Wikipedia and it says it ran from March to April '78. They DID do a 90 minute show in Oct. '76. Funny...I remember living in Alabama when that came on....Must be the Alzheimers...Sometimers?...Whaaaaatever. )