Two years ago, I had that problem with a few batches of Lansinoh bags, but I called the company and they sent me replacement boxes. I still use the Lansinoh bags, since they're the only ones I like. I haven't had a problem with any of the new ones this time. Just in case, I thaw my milk in a clean ziplock bag, so if it does leak I'm not wasting milk. Also, how are you freezing them-do you lay them flat somewhere in your freezer or use a storage box? I think my bags were getting tiny tears from being pinched in the storage box, so I stopped stuffing my storage box so full and haven't seen a leak. I did have a bag leak that I had just laid flat in my freezer. When I pulled it out, it had stuck to the things I laid it on and was hard to pick up and that stressed one of the seams enough to cause a leak. I'd stick with the Lansinoh bags, call them for replacements and use a ziplock as back-up. Good luck!