I deleted the world and restored back to a very older version and deleted the buildingplanner folder under plugins to get the startup messages away and to have the world sort of back to normal.. but then when I created a sign (10x10x60) and thought it was too small I destroyed it and the server gave me the following error:

20:52:56 [INFO] [Spout] Successfully authenticated fabiozaza's Spoutcraft client
. Running client version: 1.0.6.449
20:57:31 [SEVERE] java.lang.IllegalStateException: TickNextTick list out of sync
h
20:57:31 [SEVERE] at net.minecraft.server.World.a(World.java:2122)
20:57:31 [SEVERE] at net.minecraft.server.World.doTick(World.java:1637)
20:57:31 [SEVERE] at net.minecraft.server.MinecraftServer.h(MinecraftServe
r.java:454)
20:57:31 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftSer
ver.java:374)
20:57:31 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(Sour
ceFile:417)
20:57:31 [SEVERE] Unexpected exception
java.lang.IllegalStateException: TickNextTick list out of synch
at net.minecraft.server.World.a(World.java:2122)
at net.minecraft.server.World.doTick(World.java:1637)
at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:454)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)
20:57:36 [INFO] [BuildingPlanner] Saving area: Testing Area, planning, owned by
fabiozaza, at x:5, z:437, y:64

I've made the switching from commit to uncommit a bit slower now so that the server can actually keep up.. that goes for the destroy process too. When I release 0.5.1, let me know if you get this problem again.