The bug
You can't accurately set the sliders. This is the case with quite some sliders in the game, it may require rewriting the sliders in the game.
How to reproduce
Create a custom world and go to page 2, there under dirt select the min height you can either choose 21 or 23 but not 22.
Linked issues
relates to 1
Attachments
Comments 5
Confirmed in 1.8.1-pre5.
Maybe this is related with MC-69990?
Is this still happening in 1.8?