MC server crash log

2013-05-02 23:43:21 [INFO] Stopping server
2013-05-03 21:03:06 [INFO] Starting minecraft server version 1.4.7
2013-05-03 21:03:06 [WARNING] To start the server with more ram, launch it as "java -Xmx1024M -Xms1024M -jar minecraft_server.jar"
2013-05-03 21:03:53 [INFO] Loading properties
2013-05-03 21:03:53 [INFO] Default game type: SURVIVAL
2013-05-03 21:03:53 [INFO] Generating keypair
2013-05-03 21:03:59 [INFO] Starting Minecraft server on *:25565
2013-05-03 21:05:37 [INFO] Preparing level "world"
2013-05-03 21:05:39 [INFO] Preparing start region for level 0
2013-05-03 21:05:40 [INFO] Preparing spawn area: 2%
2013-05-03 21:05:41 [INFO] Preparing spawn area: 18%
2013-05-03 21:05:43 [INFO] Preparing spawn area: 47%
2013-05-03 21:05:44 [INFO] Preparing spawn area: 76%
2013-05-03 21:05:44 [INFO] Done (7.320s)! For help, type "help" or "?"
2013-05-03 21:05:50 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2013-05-03 21:06:00 [INFO] User crazydude991 connecting with mods [MFReloaded|CompatSufficientBiomes, BiblioCraft, RedPowerWiring, OmniTools, TwilightForest, BuildCraft|Transport, ChargePads, RedPowerCompat, WR-CBE|Core, MFReloaded|CompatIC2, RedPowerLogic, ObsidiPlates, ThermalExpansion|Energy, Thaumcraft, drceph.petrogen, Forestry, WR-CBE|RedPower, EnderStorage, XyCraftWorld, GraviGun, BinnieCore, AdvancedMachines, MFReloaded|CompatPams, mmmPowersuits, IronChest, MFReloaded|CompatRP2, BuildCraft|Energy, GregTech_Addon, Railcraft, ImmibisCore, EE3, MiscPeripherals, PortalGun, ChickenChunks, ModularForceFieldSystem, factorization, RedPowerLighting, AppliedEnergistics, RedPowerBase, MFReloaded|CompatExtraBiomes, MFReloaded, MFReloaded|CompatXycraft, XyCraft, ThermalExpansion, NetherOres, BuildCraft|Silicon, ThermalExpansion|Transport, GraviSuite, XyCraftMachines, BuildCraft|Core, IC2NuclearControl, ThermalExpansion|Factory, MFReloaded|CompatForestry, IC2, SecretRoomsMod, ExtraBees, StevesCarts, ExtrabiomesXL, Mystcraft, ComputerCraft, WR-CBE|Addons, AdvancedSolarPanel, BuildCraft|Factory, RedPowerMachine, XReliquary, SoulShards, RedPowerCore, MFReloaded|CompatThaumcraft, CCTurtle, Tubestuff, RedPowerControl, MFReloaded|CompatTwilightForest, MFReloaded|CompatSoulShards, RedPowerWorld, BuildCraft|Builders, PowerConverters]
2013-05-03 21:06:02 [INFO] crazydude991[/86.7.134.176:57921] logged in with entity id 183 at (665.5175112310616, 115.89118522585548, -7.665732449620957)
2013-05-03 21:06:13 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2013-05-03 21:06:43 [INFO] crazydude991 lost connection: disconnect.genericReason
2013-05-03 21:09:22 [INFO] Stopping the server
2013-05-03 21:09:22 [INFO] Stopping server
2013-05-03 21:09:22 [INFO] Saving players
2013-05-03 21:09:22 [INFO] Saving worlds
2013-05-03 21:09:22 [INFO] Saving chunks for level 'world'/Overworld
2013-05-03 21:09:22 [INFO] Saving chunks for level 'world'/Nether