From an interview with Troy Baker, the new voice of James Sunderland in the HD version, about original actor Guy Cihi:
He wanted non-existent money that he felt that he was owed,” he explained. “And [Konami] wanted to use him again. Guy was the one who was outspoken about it and said that unless this happens he wouldn’t do it, so he forced Konami’s hands.
There’s a comparison available somewhere.1 Ah, here it is.
What’s not clear to me is if Cihi was the only voice actor replaced or if they replaced all the actors. And if the problem was with Cihi wanting resiudals why replace all the actors?