Basically we have a multiplayer server running on a linux dedicated VDS (Ubuntu 13.10 fully updated) and it seems that when more than one person is on the server, it starts kicking people with the following error:
Internal Exception: io.netty.handler.timeout.ReadTimeoutException

It happens almost constantly the minute we hit 5 people or more on the server. With one or two, it's not too bad, and it seems certain people get it more often than others. I should note, it generally happens right after people connect but sometimes it's just random.

The logs don't explain much as to what's going on.

I'm getting these errors a lot in my client log:
[17:42:24] [Client thread/WARN]: Unable to play empty soundEvent: minecraft:music.menu
[17:49:51 INFO]: Client> [17:49:51] [Client thread/ERROR]: Item entity 1536725 has no item?!
[17:50:27 INFO]: Client> [17:50:27] [Client thread/ERROR]: Item entity 1537704 has no item?!

There's nothing explaining the crash client side. No errors or anything besides the one that pops up on minecraft itself which I've wrote above.

The server logs just show people disconnecting like this:
[18:59:41] [Server thread/INFO]: Player2 joined the game
[19:00:03] [Server thread/INFO]: Player1 lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[19:00:03] [Server thread/INFO]: Player1 left the game

I've tried completely reinstalling minecraft, both deleting the exe and the .minecraft folder and starting fresh. Still happens. I've tried redownloading the minecraft_server.1.7.2.jar file but that didn't help. I've been trying to google it, but it's been boggling me for days now.