I'm going to go down the list of all your plugins-
AngryWolves- This shouldn't interfere with anything
AutoKick- May be having issues... It is for CraftBukkit 1.2.5 R1
bpermissions- Overly Complicated... Get GroupManager
cm_audioclient_v0.9- Erm, Not nescary
ColorMe- I dont think this is compatible with essentials
Essentials- Needed
Mob Disguise- Cool, You can keep
PluginMetrics- Noy sure what it is
SimplePrefix- Comes with "GroupManager"
SimpleHat- Already In essentials /hat
SimplyPerms- Could be the source of your problems... Get groupmanager!
Ok, So the moral is...
Delete- bPerms, SimplyPerms, SimplePrefix, SimpleHat, And maybe colorme
Keep- AngryWolves, AutoKick, Essentials, MobDisguise, WE, WG,
Iffy- ColorMe, Audiomods,
~Gar