A lot of our bikes have died due to moisture seepage into the CDI. It seems that hairline cracks form in the resin that seals the unit. This usually happens while riding in the rain because moisture is forced up under the tank area. I would not however, rule out the possibility that your CDI was affected by moisture even while standing still in the rain.
Oh, and if the CDI is the problem, it can be dried out and sealed so you're good to go.
