It looks like CBS/NYT is so concerned that they might be labelled "liberal" media that they are suppressing good news for Kerry. This from MyDD:
"The word I hear is that NYT/CBS are not going to release their latest FL survey, because it shows Kerry up by 4 points. Apparently, they [CBS & NYT's] think that is an implausible result, so they are suppressing it. Of course, it's not implausible at all. And imagine the reverse: would they have suppressed a poll showing Bush up 4?"