Citizens / iConomy help

ok i have

economy:
use-econplugin: 'true'
use-economy: 'true'
prices:
blacksmith:
creation:
item: '10'
econplugin: '35000'
item-currency-id: '37'
toolrepair:
item: '10'
econplugin: '500'
item-currency-id: '266'
armorrepair:
item: '10'
econplugin: '1000'
item-currency-id: '37'
basic:
creation:
item: '10'
econplugin: '10000'
item-currency-id: '37'
guard:
creation:
item: '10'
econplugin: '300000'
item-currency-id: '37'
wizard:
creation:
item: '20'
econplugin: '95000'
item-currency-id: '37'
changetime:
item: '20'
econplugin: '1500000'
item-currency-id: '37'
spawnmob:
item: '20'
econplugin: '600'
item-currency-id: '37'
teleport:
item: '20'
econplugin: '2000'
item-currency-id: '37'
togglestorm:
item: '20'
econplugin: '15000'
item-currency-id: '37'
trader:
creation:
item: '20'
econplugin: '250'
item-currency-id: '37'
bandit:
creation:
item: '10'
econplugin: '100'
item-currency-id: '37'
healer:
creation:
item: '10'
econplugin: '100000'
item-currency-id: '37'
heal:
item: '10'
econplugin: '1000'
item-currency-id: '37'
levelup:
item: '10'
econplugin: '100'
item-currency-id: '37'
quester:
creation:
item: '10'
econplugin: '100'
item-currency-id: '37'


when i spawn an npc this pops up.
java.labg.nockassdefffounderror:
could not inialize class com. citizens.economyhandler.

it still spawns the npc. the same thing pop's up when i try to /npc trader or any other job but does not change the job of that npc. it only started this when i downloaded and enabled iConomy.

my question is. how do i get it so that i can spawn a trader and so that the trader will use Currency for his items without the error poping up i would really like to beable to make an ingame currency so that i dont need to carry items to buy items...