There's "supposedly" some controversy around what Donald says. The line is like doggone "stubborn little--," and it cuts off at little. At the same time however, there are some, myself included, that here "you GD stupid Nword" and says the N word. What makes me believe in the later with the swearing + racist remark is due to the fact I watched the show as a kid. I was like 8 or so at the time, and that part sounded funny when I heard it. It was similar in sound to the monkey/gorilla opening the door and saying "Wise guy" before shaking his fist. When I watched the uncut version, the gorilla says "Wise Ass" before he shakes his fist at the protagonist who enters the club.
Funny, I always heard it as "wise ass" when I was a kid, and "little" for the Donald line. I dunno, people always like to look into/read too much/want something to complain talk about. I couldn't imagine them ever doing something THAT insincere.
The only "controversy" I ever heard on RR was the phone number of somebody written on the wall in Toon Town when Eddie was hanging in the air. It got changed when it came out on VHS (I could be remembering wrong, I don't really follow).
I think it was 1989 to 1992 when I heard it as a kid (I was 6 to 9 at the time), and the "Wise Guy" was dubbed over since I never saw it in theaters.
To be honest, I never heard about the phone number. It's just funny what kids see, and then what they remember as adults. Rocko's Modern Life I enjoy a heck of a lot right now as an adult. The same can be said with Samurai Jack.