I have created a group of Business Contacts from my contacts folder. After a
while I discovered duplicate versions of the same contact in my Business
Contacts. I have deleted them several times but they re-appear. In fact if I
leave them alone they slowly start mutliplying - I have seven entries of one
of them. New copies appear evry few days. Also, I have Accounts that are
mutiplying no matter how many times I delete them.

What is causing this to happen and how to I stop it?