When the Taliban were in power, they destroyed opium production. Now they're using it to fight us.?

Opium poppy production in Aphganistan is at record highs. When the Taliban first took over, they made a big (negative) impact on poppy production, so much that the Bush admin gave them $43,000,000 in the months before 9/11 to help them. Now, they're using the money from the poppies to finance their fight against the allied forces occupying the country. What went wrong? How did U.S. policy/strategic thinking screw up so badly? Did the administration take its eye off the ball in its eagerness to go after Saddam? What be done?