In case it gives anyone some ideas while I'm asleep/at work, here's the last part of my log when I get booted:
2013-02-25 23:47:26 [INFO] [STDOUT] Loaded codechicken.wirelessredstone.addons.NEIWirelessAdd onConfig
2013-02-25 23:47:32 [WARNING] [FZ] No renderer for ID 5
2013-02-25 23:47:42 [INFO] [PortalGun] [1.4.7v2] Received world props from server.
2013-02-25 23:48:13 [WARNING] [FZ] No renderer for ID 0
2013-02-25 23:48:26 [INFO] [STDERR] java.net.SocketException: Connection reset
2013-02-25 23:48:26 [INFO] [STDERR] at java.net.SocketInputStream.read(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at java.net.SocketInputStream.read(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at java.io.FilterInputStream.read(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at org.bouncycastle.crypto.io.CipherInputStream.nextC hunk(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at org.bouncycastle.crypto.io.CipherInputStream.read( Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at java.io.DataInputStream.readFully(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at java.io.DataInputStream.readFully(Unknown Source)
2013-02-25 23:48:26 [INFO] [STDERR] at cz.a(SourceFile:2
2013-02-25 23:48:26 [INFO] [STDERR] at ef.a(Packet.java:166)
2013-02-25 23:48:26 [INFO] [STDERR] at cg.i(TcpConnection.java:320)
2013-02-25 23:48:26 [INFO] [STDERR] at cg.c(TcpConnection.java:540)
2013-02-25 23:48:26 [INFO] [STDERR] at ch.run(SourceFile:93)