Years ago - it was before Phantom Menace but I was with bugshaw so I'd guess 1997 or so - we went to see Phil Jupitus do a show on Star Wars, in which Wookie Tourette's Syndrome was one of the explanations he put forward as to why Chewbacca never had his lines translated. The others included that he was flamboyantly gay and making continuous suggestive remarks, or that he was a chain-smoker permanently moaning about how it was time for a cigarette (as Jupitus pointed out, Chewbacca's bandolier does appear to be made of alternating Silk Cut packets and lighters.)