re: Media never errs in favor of Bush meme....
Here are a couple links to someone who digs into the internals of polls.
In this link, he examines in pretty good detail the internals of the Newsweek poll. In this link, he addresses Rasmussen directly.
Are the Time and Newsweek polls accurate? Probably not. Are any of the polls accurate? I doubt it. I'm much more interested in a state by state analysis rather than a national popularity poll.