I thought Matt Cutts mentioned that the canonical issue was fixed with the Jagger update. At least as far as the duplicate content issue. As far as PR leak, yes you would want a 301 redirect. Unfortunately if you are on a Windows server it isn’t that easy. My host is dumfounded, so I’ve given up trying, I know it can be done in ASP fairly easily (have done it for sites outside of this industry and for other reasons than PR), but not sure if it is the right method to please Google.