I'm having similar problems with my server.
What if Forge is indeed the latest "recommended build"?
Does it have to be EXACTLY Forge 1.3.3, or can it be 1.3.3.12?
[SEVERE] Unexpected exception
java.lang.NoSuchMethodError: forge.ISpecialArmor.getProperties(Lhk;II)Lforge/ArmorProperties;
at hk.c(EntityPlayer.java:773)
at lx.a(EntityLiving.java:482)
at hk.a(EntityPlayer.java:686)
at ft.a(EntityPlayerMP.java:163)
at lx.b(EntityLiving.java:694)
at hk.b(EntityPlayer.java:1294)
at se.a(Entity.java:616)
at ft.b(EntityPlayerMP.java:397)
at lf.a(NetServerHandler.java:253)
at iu.a(SourceFile:126)
at pd.b(NetworkManager.java:234)
at lf.a(NetServerHandler.java:49)
at ew.a(SourceFile:108)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:446)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:346)
at cz.run(SourceFile:465)
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This is the error my server gets before crash