It was November 2011, my furnace making noise for a bit then worked normal again. The loud noise starts bother my wife, so I called Air One Heating and Cooling Inc. The technician seems very knowledegable on this sort of problem. He told us the problem was the burner, it causes the loud noise between the metal parts. He explains to us when it heats up evenly, the noise would stops.
The furnace works great and quiet. The best thing is no more noises coming from the furnace. I highly recommend Air One Heating and Cooling for any of your furnace problem.