The glitch is, if you play your Pokémon Ruby/Sapphire for more than a year, your berry will stop growing. To make then get back to grow, you can connect to a Pokémon Colloseum (sorry if it´s writed wrong).
Basically after a year's play berries stop growing. you need to link with Coloseum, Channel (Jerachi IS the berry fix!), got the shiny zigzagoon from the berry fix event they did or do it through linking and enabling the berry fix in FR/LG/E.