If you put a decimal (say 1.5) for landsize, you get the following error:

2011-10-04 10:28:55 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'mv' in plugin Multiverse-Core v2.0-b271
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:163)
at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:358)
at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:92)
at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:471)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)
Caused by: java.lang.NumberFormatException: For input string: "1.5"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.valueOf(Unknown Source)
at com.Khorn.PTMBukkit.Util.ConfigFile.ReadModSettings(ConfigFile.java:63)
at com.Khorn.PTMBukkit.WorldConfig.ReadConfigSettings(WorldConfig.java:277)
at com.Khorn.PTMBukkit.WorldConfig.(WorldConfig.java:154)
at com.Khorn.PTMBukkit.PTMPlugin.GetSettings(PTMPlugin.java:121)
at com.Khorn.PTMBukkit.PTMPlugin.getDefaultWorldGenerator(PTMPlugin.java:76)
at com.onarandombox.utils.WorldManager.getChunkGenerator(WorldManager.java:146)
at com.onarandombox.utils.WorldManager.addWorld(WorldManager.java:77)
at com.onarandombox.MultiverseCore.commands.CreateCommand.runCommand(CreateCommand.java:65)
at com.pneumaticraft.commandhandler.CommandHandler.checkAndRunCommand(CommandHandler.java:245)
at com.pneumaticraft.commandhandler.CommandHandler.processFoundCommands(CommandHandler.java:115)
at com.pneumaticraft.commandhandler.CommandHandler.locateAndRunCommand(CommandHandler.java:70)
at com.onarandombox.MultiverseCore.MultiverseCore.onCommand(MultiverseCore.java:379)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
... 12 more

This variable INT now ..
Exception fixed.