Server keeps crashing need help!

I have a large bukkit server with 30 plugins. It has been running fine for ages. Then when 1.3.2 came out, my server keeps crashing every 24-36 hours. This is becoming very annoying to my server members . However, I do not know how to fix it. I have plenty of room left in my ram and none of the plugins are outdated. I have recieved this following crash three times. Please help! This is the crash report I recieve:
[size=50]---- Minecraft Crash Report ----
// Hi. I'm Minecraft, and I'm a crashaholic.

Time: 8/18/12 7:08 PM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: GC overhead limit exceeded
at net.minecraft.server.RegionFile.a(SourceFile:198)
at net.minecraft.server.RegionFileCache.c(SourceFile:91)
at net.minecraft.server.ChunkRegionLoader.a(ChunkRegionLoader.java:46)
at net.minecraft.server.ChunkProviderServer.loadChunk(ChunkProviderServer.java:132)
at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:76)
at net.minecraft.server.PlayerInstance.<init>(PlayerInstance.java:23)
at net.minecraft.server.PlayerManager.a(PlayerManager.java:66)
at net.minecraft.server.PlayerManager.movePlayer(PlayerManager.java:186)
at net.minecraft.server.ServerConfigurationManagerAbstract.d(ServerConfigurationManagerAbstract.java:198)
at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:420)
at fr.neatmonster.nocheatplus.CustomNetServerHandler.a(CustomNetServerHandler.java:53)
at net.minecraft.server.Packet10Flying.handle(SourceFile:136)
at net.minecraft.server.NetworkManager.b(NetworkManager.java:281)
at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:109)
at net.minecraft.server.ServerConnection.b(SourceFile:35)
at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:583)
at net.minecraft.server.DedicatedServer.q(DedicatedServer.java:212)
at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:476)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:408)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)

Relevant Details:
- Minecraft Version: 1.3.1
- Operating System: Windows 7 (amd64) version 6.1
- Java Version: 1.7.0_03, Oracle Corporation
- Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
- Memory: 119754728 bytes (114 MB) / 954466304 bytes (910 MB) up to 954466304 bytes (910 MB)
- JVM Flags: 2 total; -Xmx1024M -Xms1024M
- Type: Dedicated Server
- Is Modded: Definitely; 'craftbukkit'
- Profiler Position: N/A (disabled)
- Player Count: 21 / 100; [EntityPlayer['CaptinPacman56'/848122, l='world', x=338.00, y=71.00, z=-291.00](CaptinPacman56 at 338.0,71.0,-291.0), EntityPlayer['HEROICNOBLE'/798792, l='world', x=338.00, y=71.00, z=-291.00](HEROICNOBLE at 338.0,71.0,-291.0), EntityPlayer['awelkinator'/884940, l='world', x=338.00, y=71.00, z=-291.00](awelkinator at 338.0,71.0,-291.0), EntityPlayer['awelkinator'/909178, l='world', x=338.00, y=71.00, z=-291.00](awelkinator at 338.0,71.0,-291.0), EntityPlayer['hero_6000'/847606, l='world', x=338.00, y=71.00, z=-291.00](hero_6000 at 338.0,71.0,-
[b]Then the server crash goes on and on about all the entities in my five worlds (for over 200 lines until you get to this)[/b]
- World hg3 Players: 0 total; []
- World hg3 Chunk Stats: ServerChunkCache: 650 Drop: 0
NOTE: This usually happens when I get more people on the server then usual, however, it sometimes happens when there is no one on.