Though I am not a Minecraft player, I was intrigued by this bug, so I went on a forum hunt. Conclusions:
Am I the only one with this problem?
Seems the problem is common:
And even sometimes occurs in other Java applications:
Do I HAVE to reboot?
Some people report that either
- Logging off and on from the Windows account
- Physically disconnecting and reconnecting the network cable
Will also fix the issue.
What causes it?
Some people claim it's a bug in the network driver, a limitation of a specific router, an issue with a specific modem, an over-saturation of network connections, a Java bug, a Windows bug... and all these people show that fixing the single thing they claim caused the problem, fixed the error :\
The truth appears to still be unknown, and the reason might even be different for different people, even though the symptoms are the same.
How do I solve it?
Different solutions appear to work for different people... here's a short summary of solutions that worked. I suggest trying one at a time and hoping one of them will work. Each of the solutions listed below have worked for more than one user but haven't worked for others.
Update the network adapter
The best thing I could find is this thread on the minecraftforum.net, and I advise reading it. Basically it suggests updating your network adapter drivers, and gives a good explanation of how to do it correctly for each of the affected cards.
Run the server from a virtual machine
The same thread as above suggests that if things still don't work, running the server inside a virtual machine - which is running something that isn't Windows XP - should work.
Use a different network adapter
Another solution which seemed to have worked for more than one player is using a different network card.
Buffer the network packets sent by Minecraft
In this thread, a user analyzes the connection and proposes to use an application to buffer the packets. He even wrote that application and uploaded it - maybe it's worth giving it a go.
Change network adapter settings
The following solution, taken from here, seemed to have worked for more than one user - even those not using an Atheros card (just find comparable settings):
Go to My Computer and right click on the icon.
Click on Properties.
Click on the Hardware tab, then click on the Device Manager button to open the Manager.
Click the little (+) icon next to Network Adapters.
Find your network adapter. For me it's called Atheros AR8121/AR8113 PCI-E Ethernet Controller.
Right click on it and go to Properties.
Click on the Advanced tab.
You should see a list of properties on the left and a combo box on the right.
In the properties list, click on Flow Control.
Make sure that is set to Off.
Next check the Max IRQ per Second and make sure that it's set to 5000.
Also check that Maximum Frame Size is set to 1514.
Now click on Number of Rx Buffers. Change this to the maximum value that it will support.
Do the same for the Number of Tx Buffers.
Best Answer
These are bugs, and it has been submitted to the Mojang Issue Tracker: