Crashreport: ConcurrentModificationException

[Milso]

Operating System: Linux (amd64) version 2.6.32-042stab044.17
Hosted on Creeperhost.net VPS
Running FTBBettaA (20-11-2012)
Added Mods: Logistic Pipes
Server Specs:
Xeon L5420
5.5GB of ram

Today I got a random crash and was wondering if any one else could shed some light on it.

Description: Exception in server tick loop
 
java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
    at java.util.ArrayList$Itr.next(Unknown Source)
    at xe.h(World.java:2016)
    at ie.h(WorldServer.java:463)
    at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:649)
    at hg.r(DedicatedServer.java:241)
    at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:585)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:492)
    at fp.run(SourceFile:818)

 

[Oratory]

I think this is the error i got when i added logistics pipes aswell.
What i did to get Logistics pipes to work was to change the item ID of "LogisticsPipes Sign" to 2008 and "LogisticsPipes Solid Block" to 2009

You can find these at the following lines: 393 and 402, or just search for the text within the " "

 

[Milso]

Oratory you saying its a block ID conflict?

The server normally runs and only got this error 2 times now last one was about a week ago.

and FYI

logisticssignid {
  # The ID of the LogisticsPipes Sign
  block=581
}
logisticssolidblockid {
  # The ID of the LogisticsPipes Solid Block
  block=580
}