What was the problem?

We think it was the datacenter. We aren't sure, I tried to type something into the server chat and tank recorded this error:
012-02-06 12:56:38 [SEVERE] java.lang.NullPointerException
2012-02-06 12:56:38 [SEVERE] at net.minecraft.server.ItemStack.damage(ItemStack.java:172)
2012-02-06 12:56:38 [SEVERE] at ic2.common.ItemArmorQuantumSuit.performQuantum(ItemArmorQuantumSuit.java:46)
2012-02-06 12:56:38 [SEVERE] at net.minecraft.server.mod_IC2.OnTickInGame(mod_IC2.java:1834)
2012-02-06 12:56:38 [SEVERE] at ic2.platform.Ic2.OnTickInGame(Ic2.java:41)
2012-02-06 12:56:38 [SEVERE] at net.minecraft.server.ModLoader.OnTick(ModLoader.java:682)
2012-02-06 12:56:38 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:407)
2012-02-06 12:56:38 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
2012-02-06 12:56:38 [SEVERE] Unexpected exception
It is probably unrelated, so ignore it.
Then the whole damned server went down, not just tekkit, the entire machine. That is what lead use to believe it is the datacenter.
Some changes:
Removed Ptweaks. This mod was loading chunks on a player basis (more detailed than that). I had added it to cut down on RAM usage over the summer. I was saving us about 2gb of RAM but it was removed anyway to see if performance changes.
Spout Server has a been shut down and all available RAM has been given to the Tekkit server.
Changes being looked into:
The banning of TP pipes. They are causing issues and CAN crash the server.
The banning of Chunk Loader Blocks. For the same reason.
So please stop using them! (if you are)
We know someone is putting Chunk Loader Blocks down as they appear in the log.