Yannick you completely missed my point. I said says mr Mural boy because Celdur only makes mural and has only made murals since this game was discovered. So its a joke to quote his message where he wants everyone to make stuff not mural and say : says mr Mural boy.
Its really not funny when you have to explain it like that.
Yannick bobanick it looks like either your gfx card is on the fritz, you need updating to java, maybe because he coded it with the latest version, or this is a problem with the minecraft programming.