The way I read it, there are two different questions here. I thought entropy was talking about the left side sound being defective, not that the unit (there's a good for everything technical term!) was coming out of his ear.

If the unit is coming out of your ear, it is likely that your ears are of different sizes. Not so uncommon. The solutions are:

1. Return your ears to the Maker for warranty service, or
2. try one of the more expensive in the Shure like or the Ety-whaty-whosits that have those tips with a series of flanges. Shure will accept returns no questions for 30 days. Ety-macallits says, "you open it, you own it."
3. Both brands are designed so that an audiologist can make custom fitted molded ear pieces. Expensive, but I hear they really enhance the sound.

Good luck with the electronics and the organics!!