They have NOT known about this since October. I know this because it would have been posted on Free Republic .com.
Sure they have. Berger knew about it. Whoever requested the documents knew about it. Whoever the archivist contacted ( a dem) knew about it. Somebody had to notice that berger's home was searched by the FBI.
As an advisor to Kerry, Berger was obligated to inform him of the possible embarrassment. Hillary knew (remember her very odd reference to the election being decided by "events"?)