This report details some of the factors, but is focussed on pinning the blame on George Bush. But that is only one ideological lens through which the issue can be framed.
Another might be to ask why the push for biofuels in the first place?
And that lens of analysis leads solidly to the dangers of the AGW myth and the inherent dangers of seeking to solve a non-problem and in turn creating a very real, observable problem instead.
Enough to convince anyone to turn skeptic