A La Jolla investment broker was sentenced today to 6 1/2 years in prison for fraud arising from the loss of his clients' funds -- some people lost their life savings -- through on-line trading. James Yiu Lee, 59, solicited clients through a string of false representations, including claims that he was a wealthy attorney with numerous graduate degrees who had significant trading experience, and failed to disclose a previous conviction for defrauding investors, according to prosecutors.