Exception in server tick loop

Minecraft has crashed!
----------------------

Minecraft has stopped running because it encountered a problem; Exception in server tick loop

A full error report has been saved to C:\Documents and Settings\Claudio\Dados de aplicativos\.minecraft\crash-reports\crash-2013-04-14_11.04.50-server.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash 😞

— BEGIN ERROR REPORT ab50ffce --------
Full report at:
C:\Documents and Settings\Claudio\Dados de aplicativos\.minecraft\crash-reports\crash-2013-04-14_11.04.50-server.txt
Please show that file to Mojang, NOT just this screen!

Generated 14/04/13 11:05

– System Details –
Details:
Minecraft Version: 1.5.1
Operating System: Windows XP (x86) version 5.1
Java Version: 1.7.0_17, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 269520 bytes (0 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 2288 (128128 bytes; 0 MB) allocated, 2288 (128128 bytes; 0 MB) used
Suspicious classes: IWrUpdater, Config, WrUpdates, ...[reifnsk.minimap.ReiMinimap, GuiScreenInterface, GuiOptionScreen, ...]
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
Profiler Position: N/A (disabled)
Vec3 Pool Size: 360 (20160 bytes; 0 MB) allocated, 360 (20160 bytes; 0 MB) used
Player Count: 1 / 8; [jc['victorsocs'/139297, l='SURVIVU', x=-132,50, y=66,00, z=245,50]]
Type: Integrated Server (map_client.txt)
Is Modded: Very likely; Jar signature invalidated

java.lang.OutOfMemoryError: Java heap space
at bs.<init>(SourceFile:12)
at acj.a(SourceFile:216)
at acj.a(SourceFile:89)
at iy.b(SourceFile:152)
at iy.a(SourceFile:179)
at iz.a(SourceFile:623)
at net.minecraft.server.MinecraftServer.a(SourceFile:256)
at bjh.q(IntegratedServer.java:166)
at net.minecraft.server.MinecraftServer.run(SourceFile:331)
at gp.run(SourceFile:573)
— END ERROR REPORT 524f94b0 ----------