The CBS Poll has Kerry up 49-43. Their July 11-12 poll was Kerry 49-44. In the polling world, CBS is infamous for oversampling Democrats. SOmetimes by 10 points or more. I don't see how The Kerry people can see this as anything but bad news.
The Newsweak poll also oversampled Democrats. More generally, there are very few national polls that I now trust. Gallup is still one of them -- they are at the national level what Mason Dixon and a few other independent firms are at the state by state level. I also still trust the poll that AP uses. I used to trust the ABC/Washington Post poll as well, but this year they have started to cook their polls, ususally by oversampling Democrats and Independents at the expense of Republicans. Now one can safely disregard this poll, the CBS/NYT "poll," and the LA Times "poll." As for Zogby, I wouldn't even call what he does as polling.