Large Pits in Ground: Look Like Worldholes but Not

[abc9939]

Title: Large Pits in Ground: Look Like Worldholes but Not

Version: 3.1.2

OS: Windows 7

Java Version: 32bit

Description of Problem:

I have been getting large pits in the ground that look like worldholes but have grass and trees at the bottom just over bedrock. I even found a few chickens down there. This was in singleplayer, so i apoligize if this is all just stupid me not playing a multiplayer mod in multiplayer. These holes are everywhere, even in mountain biomes. There are large mountains with holes strait down the middle or side. There is water and lava from caves streaming down the sides, but water from the rivers, lakes, and oceans on the surface gets cut off and doesn't flow down. I have screenshots, but me being new to the forums, I don't know how to post them. I quit and came back and they were still there. I found an abandoned mineshaft running through one. That and the trees and grass at the bottom seemed to be the only things that didn't get cut off.

I don't know if this is my fault for using tekkit in singleplayer, or some weird kind of bug.

Please tell me what this is,

abc9939

Error Messages:

Error Log:

[abc9939]

Oh sorry, java version 7