CraftBukkit version: 1.4.5 Beta 0.2
Plugin list: BattleKits
BattleKits version: 1.8 (BukkitDev pre-approved file)
Config file link (pastebin.com): Does not make/load a config
Server log link (pastebin.com): Ill just paste it here (the error of course)

2012-12-07 23:01:54 [SEVERE] Could not load 'plugins\BattleKits (2).jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NullPointerException
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:152)
at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)
at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:227)
at org.bukkit.craftbukkit.CraftServer.(CraftServer.java:205)
at net.minecraft.server.ServerConfigurationManagerAbstract.(ServerConfigurationManagerAbstract.java:51)
at net.minecraft.server.ServerConfigurationManager.(SourceFile:11)
at net.minecraft.server.DedicatedServer.init(DedicatedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:398)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:856)
Caused by: java.lang.NullPointerException
at com.lavacraftserver.BattleKits.BattleKits.(BattleKits.java:28)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:148)
... 9 more

When does the error occur? Startup

Steps to reproduce error: Run Server?

Any other relevant info:
The " (2).jar" suffix does not change its startup state.
With or without, it does not load.

Cheers for the informative report, I'll look into it

Right, figured out the issue.

Fixed http://199.241.30.86:2020/job/BattleKits/1585/
95c81b1

Re-open if the issue persists :)