A new update for Pokémon Tretta Lab for Nintendo 3DS is now available on the Japanese eShop. The Version 1.1 patch fixes some scanning accuracy issues.

Version 1.1 QR Code - Update Procedure

Instructions	QR Code
1. Turn on the camera by pressing the button (R or) L in the "HOME MENU". 2. Touch the two-dimensional code reader at the bottom left of the screen. 3. To read the QR code, use the camera and line up the code.

Source: http://www.pokemontretta.com/goods/dssoft.html