I spent a little time on DU this morning (and showered afterward). The prevailing theories are:
Inequitable distribution of voting machines
and (get out your tin foil)
The Diebold voting machines were rigged ... which is also their explanation for the discrepencies between exit polling and raw votes.
It really was enjoyable going over there and seeing the meltdown first hand
Did you bring your disinfectant?
Are they allowing visitors on their forum yet?