World Generation Glitch (Flat Wall)

Ok so I'm currently got a brand new Windows 8 Desktop and i have the right java and when I start the server up there are no errors and it starts up fine. When I quit out and exited the start.bat command menu and I started it back up again and when i joined I saw what you see below in some places... Most of the time it happens after I quit then start the server up again... I've tried doing different world names to try having a different world the same thing happened. I even took it a step farther by deleting my whole Server folder and doing everything from scratch again. It still does these "Wall" Like cliff bugs. I can break the blocks on the side and stuff. I'm currently running CraftBukkit 1.6.2 R0.1 the recommended Beta version. I have done this with plugins and without they have no role in this. Please help me you would save me..... In the background of the pictures it looks like its not rendering or loading properly but I took a screen shot soon as I appeared at this.

 

Try doing /save-all before stopping the server. Also use /stop to stop it, don't just close the window.

 

Your world seed was somehow changed. Might be something else, but that's what it looks like.

 

What happens if internet problems or something or i accidently shut down the server, will this happen then every time???