Updated: the Star Tribune has corrected the number of challenges, adjusting the number of challenges in Renville from 476 to 2. I leave the OP below for reference:
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The number of ballots challenged by the Coleman campaign stayed almost constant in the last update, while the Franken ones have skyrocketed (they roughly doubled this morning with just 1% more votes recounted). This is in itself very strange.
But it gets worse. The bulk of the new challenges comes from the small county of Renville, where the Franken campaign, according to the Star Tribune website, challenged 476 votes (the total votes recounted add up to about 6200 for both candidates). What is worse, excluding this massive amount of challenged votes, there was almost no difference in the candidate totals (Coleman lost one vote, Franken won one). In other words, these 476 challenges are votes which WERE NOT COUNTED AT ALL IN THE FIRST COUNT ON ELECTION NIGHT.
So there are two options: (1) an error in the reporting of the Star Tribune, whatever the source of the error; or (2) a massive amount of votes which were not counted on election night have popped up and are being challenged.
Link:
http://ww2.startribune.com/news/metro/elections/returns/2008/recount/msenco.htmlPlease post if you see any news or explanation about this. These 476 mysterious votes are more than enough to change the outcome of the election.