Originally Posted by Hoopdriver

I wouldn't drill relief holes just yet, but instead just watch for a while. The big question is how the cracks happened. Assuming that the post is the correct diameter, perhaps something happened during initial assembly. If the seat post is too small, flexing could have done it as would over-clamping. It's certainly worth it to get out the calipers and measure. How do the cracks line up with the post clamp?