Fake Brit: Most of the voice actors in the English-language release of the games put on fake British accents. Actual British-English test players of the game reportedly hated Lani Minella's mockney accent for Luke so much that the British edition completely redubs Luke's lines with English-born Maria Darling. Christopher Robin Miller, however, put on an accent for the Professor so convincing that many players think he is British.
Talking to Himself: The English-Language release of the games has Christopher Robin Miller taking on three parts as not only the Professor, but also Detective Chelmey and Don Paolo. Considering that in the first game, "Chelmey" was simply Paolo in disguise, this is somewhat appropriate. The Japanese games had different actors for all three characters.
Luke follows the same patch - Lani Minella (in the US versions) voices not only Luke, but also Flora, Katia, Celeste... basically all the women in the original trilogy.