Random double contacts

[Martin ClientKing]

H! When synching with Thunderbird, some of my contacts seem randomly duplicated. Phone numbers in the new entry show a hyphen (like -).

I'm sure this it happens, but not sure if it happened before.
A few days ago I emptied address books on both sides and imported all data from a csv file with the right data into MPE. After that I synched with TB so that all contacts from MPE got over ther as well.
Any idea how to prevent this from happening?
Martin

[icke1954]

Select under Phone = MPE-Client = Settings => contact-accounts to sync only a local contact account and in Thundebird only an address book, then the problem should no longer occur