Voltz Server Strange TPS Problem Help Needed

OK I am officially saying I am truly stumped on this one, and in need of some real advice.

I am having problems with TPS rates, if I join my server TPS report at 20.0 which is good, but in a short space of time I can watch this figure drop and drop until its at around 3.0 TPS.

This is the strange part, if i travel to the nether the TPS in the overworld creeps back up again until its back at 20.0

This is the same for any player of the server, I have tried the following:

- Removed the plugins - definitely not a plugin problem
- Cleared the world anchors
- Turned world anchors off
- Went to the nether and back… and still see the TPS slowly return to normal but drop again when I return to the overworld.
- Renamed the forcedchunks.dat thinking it was a chunk loading thing

-rw-rw---- 1 mc2 mc2 22 Jun 14 01:16 forcedchunks.dat
-rwxrwx--- 1 mc2 mc2 8059 Jun 14 00:04 forcedchunks.dat.old

This is the recent crashreport, i visited 211.50, 12.00, -1256.50 which was in the error. All there was a missile, removed the missile in question.

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 6/13/13 10:58 PM
Description: Ticking entity

java.lang.NullPointerException
at net.minecraftforge.common.ForgeChunkManager.forceChunk(ForgeChunkManager.java:719)
at icbm.common.daodan.EDaoDan.updateLoadChunk(EDaoDan.java:252)
at icbm.common.daodan.EDaoDan.j_(EDaoDan.java:309)
at yc.a(World.java:2291)
at in.a(WorldServer.java:647)
at yc.g(World.java:2253)
at yc.h(World.java:2107)
at in.h(WorldServer.java:516)
at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:680)
at ho.r(DedicatedServer.java:270)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:599)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:497)
at fy.run(SourceFile:849)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
at net.minecraftforge.common.ForgeChunkManager.forceChunk(ForgeChunkManager.java:719)
at icbm.common.daodan.EDaoDan.updateLoadChunk(EDaoDan.java:252)
at icbm.common.daodan.EDaoDan.j_(EDaoDan.java:309)
at yc.a(World.java:2291)
at in.a(WorldServer.java:647)
at yc.g(World.java:2253)

-- Entity being ticked --
Details:
Entity Type: ICBMMissile (icbm.common.daodan.EDaoDan)
Entity ID: 1
Name: Nuclear Missile
Exact location: 211.50, 12.00, -1256.50
Block location: World: (211,12,-1257), Chunk: (at 3,0,7 in 13,-79; contains blocks 208,0,-1264 to 223,255,-1249), Region: (0,-3; contains chunks 0,-96 to 31,-65, blocks 0,0,-1536 to 511,255,-1025)
Momentum: 0.00, 0.00, 0.00
Stacktrace:
at yc.h(World.java:2107)
at in.h(WorldServer.java:516)


From doing all this I can not work out what is going on, is there anyone out there that might be able to spread some light on what is going on before I have to restore my entire world which will do nothing but pee of all my players as they will lose their hard work


Ellis