Are you guys with the cart-related rejections getting only cart-only stuff rejected, or complete stuff? I have 2 more GBA games on the way, and one of them is SMB 4 Advance: SMB3. They better not eff that up. If they reject it, they better send back the mint/complete box NOT in a padded envelope. I was on the fence about sending that one in in the first place since I could have sold it for around $40 in the mint condition it was in. I just figured $30 with "no hassle" was better than listing and selling for a possible $40. Now I kind of wish I hadn't sent it.
From my box of 11 gameboy/gameboy advance all were cart only games and 2 were rejected for some unknown reason. It lists "severe damage" but I know they were not.