The cynic in me would say that the Taliban opposes poppy production when they're attempting to repress the farmers from a position of power, and support it when they need money to fight the government.

Not just the Taliban. The US supported government includes many warlords who derive their money from opium. And the coalition forces have pulled from from major anti-opium projects for fear of driving the farmers into the Taliban.

Quite simply, as long as the country is contested the opium will be produced. A large profit can be gained without a huge business system behind it, and history shows quite well that trying to block such things just drives up the profit.