Posted by Dusty

The only thing that looks like a bad seed error is the one with the land just stopping. The rest are regular occurrences with terrain generation because of the way most things overlap. For example something cutting into water tends to not force the water to reflow, causing just a wall of water like in a few of the screenshots. Ravines, abandoned mines, rivers and strongholds tend to intersect each other a lot, causing all sorts of ugly and broken environments.