Setting up People Picker

I have been doing some testing with configuring the People Picker and I have been unsuccessful to this point.

I have run the following command on SharePoint 2010 using STSadm.

stsadm -o setproperty -url http://cktesting.chatham-kent.ca -pn "peoplepicker-serviceaccountdirectorypaths" -pv "OU=CKMunicipality;OU=Domain Users,DC=chatham-kent,DC=ca

We have a OU called CKMunicipality and inside that OU is another one called Domain Users. When I run this command all the accounts in AD are still showing up. 

If I could get some assistance on this it would be much appreciated. Thanks.

Kim