Hmmm.. thats really weird. If the sprite is there, it suggests there is a static ref to the sprite somewhere, and the sprite collection data, material, etc. are just offshoots from that. There aren't any static references in the tk2d runtime code base either, so this is really quite puzzling. The most puzzling is the tk2dSprite itself. I'm not sure what to suggest but to start knocking out code to track it down.