I am not sure if someone already posted this or not, but here is my problem. I have started a private server. I wanted to add mods to my private server. I added modloader, modloaderMP 1.2.5 V1, minecraftforge-server V.3.2.3.108, buildcraft-server v.2.2.14 and I am using MultiMC V.3.1. All the mods are up to date. but when I start up minecraft I get this message:

Instance started with command: C:\Program Files\Java\jre6\bin\java.exe -Xmx1024m -Xms512m -cp "C:\Users\Chris\Desktop\MultiMC" MultiMCLauncher "C:\Users\Chris\Desktop\MultiMC\instances\ddfs\.minecraft" "warlord13f" 2306947992299649247
Loading jars...
Loading URL: file:/C:/Users/Chris/Desktop/MultiMC/instances/ddfs/.minecraft/bin/minecraft.jar
Loading URL: file:/C:/Users/Chris/Desktop/MultiMC/instances/ddfs/.minecraft/bin/lwjgl.jar
Loading URL: file:/C:/Users/Chris/Desktop/MultiMC/instances/ddfs/.minecraft/bin/lwjgl_util.jar
Loading URL: file:/C:/Users/Chris/Desktop/MultiMC/instances/ddfs/.minecraft/bin/jinput.jar
Loading natives...
Exception in thread "main" java.lang.VerifyError: (class: net/minecraft/client/Minecraft, method: k signature: ()V) Incompatible argument to function
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.getDeclaredFields(Unknown Source)
at MultiMCLauncher.main(MultiMCLauncher.java:61)
Instance exited with code: 1
Crash detected!

So, I decided to use minecraftforge-client V.3.1.3.102 and buildcraft-client V.2.2.14 and everything loads fine, but when I want to use the pump from buildcraft I get "There's no item ID ###. I googled, looked on youtube and I could not find anything. Would someone that has lots of experience with having there own server please help me out. I have exhausted my search's, this is my last hope.