The World Genertor will create chunk errors in a new world in 13w39b.
Seed: -5039605898113117607
Related issues
Attachments
Comments

[media][media][media][media][media][media]

Same happens to me but on my 1.6.4 server.

Attached a world created on 09/09/2013 (probably with 13w36b) and then reloaded in 13w39b. When reloading a strip of forest chunks are generated in the ocean.
When recreating that world with 13w39b, there are no wrong chunks.

@Markus B: What coordinates ?