I've had the latches on my travel humidors break off, but I wouldn't really call it breaking. The one I had, I believe it's a Herf-A-Dor, the latches actually slide off. I don't think the latch has much to do with the actual seal, other than keeping the two halves pinned to one another. As long as it latches shut, I think you'll be okay.

Now if it's actually broken, that's a different story.