As far as uncomfortable talk-show appearances go, Michael Richards' Nov. 20 mea culpa on CBS' Late Show fell somewhere between Hugh Grant on The Tonight Show and Tom Cruise on Oprah. The former Seinfeld kook appeared via satellite to offer a rambling apology to ''Afro-Americans'' for his recent comedy-club meltdown: ''I said some pretty nasty things.'' During a Nov. 17 gig at Hollywood's Laugh Factory, Richards, annoyed by the chatty crowd, recommended that one patron be thrown out because ''he's a n--ger.'' Shocked spectators yelled back, calling the 57-year-old a ''reject.'' After uttering the N-word at least six times, Richards walked off the stage. Comedian Paul Rodriguez, who was at the show, told the AP, ''Once the word comes out of your mouth and you [are not] African-American, you have a whole lot of explaining [to do].'' Factory owner Jamie Masada has banned Richards from the club it's the first time a comedian has been barred in 28 years but says that if the people Richards insulted ''forgive him, I will too.''