Bukkit

What steps will reproduce the problem?
1. I am not 100% sure what they did but I am guessing they were using an mcMMO skill of some sort, probably dying and raising their acrobatics is my guess. I just saw this error when scanning my logs over.
2.
3.

What is the expected output? What do you see instead?

What version of the product are you using?
SGTitles 1.1
Latest dev build of mcMMO at the present time:
http://ci.mcmmo.org:8080/job/mcMMO/915/

Do you have an error log of what happened?
2012-06-12 08:20:28 [SEVERE] Could not pass event McMMOPlayerLevelUpEvent to SGTitles
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:304)
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
    at com.gmail.nossr50.util.Skills.xpCheckSkill(Skills.java:197)
    at com.gmail.nossr50.util.Skills.xpProcessing(Skills.java:464)
    at com.gmail.nossr50.skills.acrobatics.RollEventHandler.processXPGain(RollEventHandler.java:103)
    at com.gmail.nossr50.skills.acrobatics.RollEventHandler.processFallXPGain(RollEventHandler.java:94)
    at com.gmail.nossr50.skills.acrobatics.AcrobaticsManager.rollCheck(AcrobaticsManager.java:46)
    at com.gmail.nossr50.listeners.EntityListener.onEntityDamage(EntityListener.java:133)
    at sun.reflect.GeneratedMethodAccessor220.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302)
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
    at net.minecraft.server.EntityLiving.a(EntityLiving.java:851)
    at net.minecraft.server.EntityHuman.a(EntityHuman.java:1134)
    at net.minecraft.server.Entity.a(Entity.java:780)
    at net.minecraft.server.EntityPlayer.b(EntityPlayer.java:467)
    at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:414)
    at net.minecraft.serverhook.NetServerHandlerProxy.a(NetServerHandlerProxy.java:99)
    at net.minecraft.server.Packet10Flying.handle(SourceFile:126)
    at net.minecraft.server.NetworkManager.b(NetworkManager.java:229)
    at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:113)
    at net.minecraft.serverhook.NetServerHandlerProxy.a(NetServerHandlerProxy.java:83)
    at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:78)
    at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:567)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:459)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: java.lang.NoSuchMethodError: com.gmail.nossr50.mcMMO.getPlayerProfile(Lorg/bukkit/entity/Player;)Lcom/gmail/nossr50/datatypes/PlayerProfile;
    at com.sgcraft.sgtitles.McMMOListener.onMcMMOPlayerLevelUp(McMMOListener.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302)
    ... 28 more

Please provide any additional information below.

Maybe its mcMMO, I am not entirely sure but just wanted to give you a heads up just in case they changed something you have to update for.