My server kicks anyone trying to use an iron furnace.

[16:40:54] [Netty IO #2/ERROR] [FML]: NetworkDispatcher exception
java.io.IOException: An established connection was aborted by the software in your host machine
at sun.nio.ch.SocketDispatcher.write0(Native Method) ~[?:1.7.0]
at sun.nio.ch.SocketDispatcher.write(Unknown Source) ~[?:1.7.0]
at sun.nio.ch.IOUtil.writeFromNativeBuffer(Unknown Source) ~[?:1.7.0]
at sun.nio.ch.IOUtil.write(Unknown Source) ~[?:1.7.0]
at sun.nio.ch.SocketChannelImpl.write(Unknown Source) ~[?:1.7.0]
at io.netty.buffer.UnpooledUnsafeDirectByteBuf.getBytes(UnpooledUnsafeDirectByteBuf.java:408) ~[UnpooledUnsafeDirectByteBuf.class:?]
at io.netty.buffer.UnpooledUnsafeDirectByteBuf.readBytes(UnpooledUnsafeDirectByteBuf.java:414) ~[UnpooledUnsafeDirectByteBuf.class:?]
at io.netty.channel.socket.nio.NioSocketChannel.doWriteBytes(NioSocketChannel.java:214) ~[NioSocketChannel.class:?]
at io.netty.channel.nio.AbstractNioByteChannel.doWrite(AbstractNioByteChannel.java:178) ~[AbstractNioByteChannel.class:?]
at io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:231) ~[NioSocketChannel.class:?]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:680) ~[AbstractChannel$AbstractUnsafe.class:?]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.flush0(AbstractNioChannel.java:260) ~[AbstractNioChannel$AbstractNioUnsafe.class:?]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:649) ~[AbstractChannel$AbstractUnsafe.class:?]
at io.netty.channel.DefaultChannelPipeline$HeadHandler.flush(DefaultChannelPipeline.java:1038) ~[DefaultChannelPipeline$HeadHandler.class:?]
at io.netty.channel.DefaultChannelHandlerContext.invokeFlush(DefaultChannelHandlerContext.java:674) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.flush(DefaultChannelHandlerContext.java:655) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115) ~[ChannelOutboundHandlerAdapter.class:?]
at io.netty.channel.DefaultChannelHandlerContext.invokeFlush(DefaultChannelHandlerContext.java:674) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.flush(DefaultChannelHandlerContext.java:655) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115) ~[ChannelOutboundHandlerAdapter.class:?]
at io.netty.channel.DefaultChannelHandlerContext.invokeFlush(DefaultChannelHandlerContext.java:674) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.flush(DefaultChannelHandlerContext.java:655) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115) ~[ChannelOutboundHandlerAdapter.class:?]
at io.netty.channel.DefaultChannelHandlerContext.invokeFlush(DefaultChannelHandlerContext.java:674) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.flush(DefaultChannelHandlerContext.java:655) ~[DefaultChannelHandlerContext.class:?]
at cpw.mods.fml.common.network.handshake.NetworkDispatcher.flush(NetworkDispatcher.java:412) ~[NetworkDispatcher.class:?]
at io.netty.channel.DefaultChannelHandlerContext.invokeFlush(DefaultChannelHandlerContext.java:674) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.write(DefaultChannelHandlerContext.java:700) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.writeAndFlush(DefaultChannelHandlerContext.java:688) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelHandlerContext.writeAndFlush(DefaultChannelHandlerContext.java:717) ~[DefaultChannelHandlerContext.class:?]
at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:893) ~[DefaultChannelPipeline.class:?]
at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:239) ~[AbstractChannel.class:?]
at net.minecraft.network.NetworkManager$1.run(NetworkManager.java:171) [eg.class:?]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:354) [SingleThreadEventExecutor.class:?]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:348) [NioEventLoop.class:?]
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) [SingleThreadEventExecutor$2.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.7.0]
[16:40:54] [Server thread/INFO] [net.minecraft.network.NetHandlerPlayServer]: ansonr lost connection: TranslatableComponent{key='disconnect.genericReason', args=[Internal Exception: java.io.IOException: An established connection was aborted by the software in your host machine], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[16:40:54] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: ansonr left the game