Although it may look it, your aerator is probably not broken. The way an aerator works is by allowing a maximum amount of air to "attack" the wine in a minimal amount of time. So they may have a number of holes or openings that allow the air into the aerator itself. If you pour the wine too fast through an aerator, that wine can seep or leak out of the sides of the aerator giving the appearance of their being a crack or imperfection with the aerator. We find this can happen easily with the Vinturi among others. Again, this is not a flaw or malfunction in anyway. But it is certainly recommend to take your time in pouring the wine slowly through the aerator as that will not only enhance the aeration process but limit any messy waste of good juice.