Problem [Monster] Block Lag

[Spidey]

Hey.

I am hosting Monster (1.0.3) on my Debian Server at the moment and getting some problems with Block Lag that occurs likely every 60 seconds.

Some info.

JVM Parameters

java -Xms3072m -Xmx3072m -XXermSize=512m -XX:ReservedCodeCacheSize=512m -XX:NewRatio=4 -XX:SurvivorRatio=3 -XX:TargetSurvivorRatio=80 -XX:MaxTenuringThreshold=8 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:SoftRefLRUPolicyMSPerMB=0 -XX:MaxGCPauseMillis=20 -XX:GCPauseIntervalMillis=250 -XX:MaxGCMinorPauseMillis=7 -XX:+CMSClassUnloadingEnabled -XX:+ExplicitGCInvokesConcurrentAndUnloadsClasses -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=50 -XX:+BindGCTaskThreadsToCPUs -XX:+TieredCompilation -XX:Tier0ProfilingStartPercentage=0 -XX:Tier3InvocationThreshold=3 -XX:Tier3MinInvocationThreshold=2 -XX:Tier3CompileThreshold=2 -XX:Tier3BackEdgeThreshold=10 -XX:Tier4InvocationThreshold=4 -XX:Tier4MinInvocationThreshold=3 -XX:Tier4CompileThreshold=2 -XX:Tier4BackEdgeThreshold=8 -XX:TieredCompileTaskTimeout=5000 -XX:Tier3DelayOn=50 -XX:Tier3DelayOff=25 -XX:+UseFastEmptyMethods -XX:-DontCompileHugeMethods -XX:+AlwaysCompileLoopMethods -XX:+CICompilerCountPerCPU -XX:+UseStringCache -XX:+UseNUMA -jar FTBServer-1.6.4-953.jar nogui

Messages that get's spammed in ForgeModLoader-server-0.log:

The world 5df1597f (funmap) may have leaked: seen 3315 times.

[Minecraft-Server] Can't keep up! Did the system time change, or is the server overloaded?

I get this messages every time when the server lags.


I understand that the Monster Pack is in beta at the moment. I just want to know if the problem is caused by a mod or by me.