Friends are getting lagged out for seemingly no reason

Friends are getting kicked out of the server randomly. I have the ports forwarded correctly and everything up-to-date, including the following plugins: Essentials, Groupmanager, ExtendDay, LWC. This occurs even with the vanilla craftbukkit. I have run the server without bukkit with no issues.
Here is the output of two different errors I am experiencing:

Code:

22:37:20 [SEVERE] at java.net.SocketOutputStream.socketWrite(Unknown Sourc
e)
22:37:20 [SEVERE] at java.net.SocketOutputStream.write(Unknown Source)
22:37:20 [SEVERE] at java.io.BufferedOutputStream.flushBuffer(Unknown Sour
ce)
22:37:20 [SEVERE] at java.io.BufferedOutputStream.flush(Unknown Source)
22:37:20 [SEVERE] at java.io.DataOutputStream.flush(Unknown Source)
22:37:20 [SEVERE] at net.minecraft.server.NetworkWriterThread.run(SourceFi
le:103)
22:37:20 [SEVERE] java.net.SocketException: Connection reset by peer: socket wri
te error
22:37:20 [SEVERE] at java.net.SocketOutputStream.socketWrite0(Native Metho
d)
22:37:20 [SEVERE] at java.net.SocketOutputStream.socketWrite(Unknown Sourc
e)
22:37:20 [SEVERE] at java.net.SocketOutputStream.write(Unknown Source)
22:37:20 [SEVERE] at java.io.BufferedOutputStream.flushBuffer(Unknown Sour
ce)
22:37:20 [SEVERE] at java.io.BufferedOutputStream.flush(Unknown Source)
22:37:20 [SEVERE] at java.io.DataOutputStream.flush(Unknown Source)
22:37:20 [SEVERE] at net.minecraft.server.NetworkWriterThread.run(SourceFi
le:103)
22:37:20 [INFO] Justin lost connection: disconnect.endOfStream

Code:

23:13:40 [SEVERE] java.net.SocketException: Connection reset by peer: socket wri
te error
23:13:40 [SEVERE] at java.net.SocketOutputStream.socketWrite0(Native Metho
d)
23:13:40 [SEVERE] at java.net.SocketOutputStream.socketWrite(Unknown Sourc
e)
23:13:40 [SEVERE] at java.net.SocketOutputStream.write(Unknown Source)
23:13:40 [SEVERE] at java.io.BufferedOutputStream.flushBuffer(Unknown Sour
ce)
23:13:40 [SEVERE] at java.io.BufferedOutputStream.write(Unknown Source)
23:13:40 [SEVERE] at java.io.DataOutputStream.write(Unknown Source)
23:13:40 [SEVERE] at net.minecraft.server.Packet51MapChunk.a(Packet51MapCh
unk.java:184)
23:13:40 [SEVERE] at net.minecraft.server.Packet.a(Packet.java:110)
23:13:40 [SEVERE] at net.minecraft.server.NetworkManager.g(NetworkManager.
java:122)
23:13:40 [SEVERE] at net.minecraft.server.NetworkManager.d(NetworkManager.
java:272)
23:13:40 [SEVERE] at net.minecraft.server.NetworkWriterThread.run(SourceFi
le:99)

I have had Time Warner run every diagnostic possible to see if my modem could be timing out or etc. and nothing is wrong on my end. As I stated the issue does not happen while running the vanilla minecraft_server.exe for days.

System information in my signature.

 

Very nice computer .
There are 2 common reasons why this could happen:
1. Too big of a map.
2. Corrupted craftbukkit.jar

Use PTweaks to help reduce your server lag, and re-install your craftbukkit.jar.

 

1. This map is quite new. I would say its only about 4-5 days old and only 5 people have been playing (no worldedit installed or anything either. World folder is only 42mb large .
2. I have replaced the craftbukkit.jar file to no avail.
Also uninstalled java 7 and reinstalled java 6 update 31 (both 32-bit and 64-bit) and the issue is still present.

Its strange since I had minecraft 1.2 running back along with craftbukkit (the version escapes me currently...) and there were absolutely zero issues, using the same domain, router settings, etc.

Plugins I am running are as follows: ExtendDay, Essentials suite (groupmanager for permissions), and LWC. Thats it!

Bump!

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Well I removed LWC, and so far there seems to be no issues. I will report these errors to the author. Hope this helps someone out there.