Slowly working through them as I play before work starts
Animal Crossing: Wild World
Bomberman
Castlevania: Dawn of Sorrow
Castlevania: Order of Ecclesia
Castlevania: Portrait of Ruin
Children of Mana
Chrono Trigger
Contact
Contra 4
Cooking Mama
Cooking Mama 2 Dinner with Friends
Diddy Kong...
I've got two Micro's myself (Original launch and Anniversary edition) and I've never had an issue with either one, they see alot of use in the summer months and my headphones always work good in them. Could be just localized to your Micro? Perhaps a loose connection on the jack itself?