First, I'll flip the chart so the headers are less of a problem (though the first looks fine to me and the "pre" block should display correctly on any browser.)
EAST SOUTH MIDWEST WEST
% Returning Bush voters (NEP) 36% 49% 43% 43%
Total voters in 2004 (Bush + Kerry) 26128705 38076883 30676093 26173241
Number of Returning Bush voters 9406333 18657672 13190719 11254493
Number of votes Bush got in 2000 9237792 17580345 13162586 10475279
-3% mortality 8960658 17052934 12767708 10161020
Number of zombie voters 445675 1604738 423011 1093473
Percent of zombies (NEP poll "error") 4.74% 8.60% 3.21% 9.72%
OK, now as to what is going on here: NEP adjusted their poll without bothering to check how many people actually voted for Bush in 2000. As a result, their numbers are way out of whack. In fact, they are quite outside the MOE for this question, even assuming 100% of living Bush 2000 voters voted in 2004, which is a stretch in and of itself.
As to the numbers from previous NEP weightings. I don't know if the regional breakdown was included in the earlier weightings. I do know that if you run the full national numbers from one earlier weighting, you don't get nearly as many zombies (in fact, you have to subtract mortality to get any, whereas here, there are zombies even before you do) and I believe you end up within the MOE on this question.
The implications are unclear. The final weighting adjustment was drastic, yes, but the weighting problems might have started earlier than that.
I generally tend to avoid party affiliation questions because they don't have as much bearing on presidential vote as people seem to think. There are plenty of cross-voters and ticket splitters in both directions (one county I analysed in Ohio had a bunch of people voting Kerry plus a Republican down-ticket, so the opposite of "dixiecrats" do exist.) The end result could be anywhere. Anyway the suddenness of the late weighting can be shown just as well through this question.
As far as "better things to do," me too. But noone seems to want to adopt this seriously, and it is quite compelling to go to the CNN website, see numbers that are currently still posted, do grade school math, and produce results that are quite perturbing. After reading an article on KoS recently I was astounded at how many people on both sides of the fence over there are just not up to speed. So don't underestimate the tactical value of a can full of worms at this juncture. We aren't losing people, but they are getting tired, and some late "converts" could charge things back up a little.
(EDIT: typo)