All messed up with mail/address book

1. I have 3 different G mail accounts, and the addresses used to show in mailboxes under inbox and under sent, on the left in the Mail window,

now I can't tell you what I changed but they are not there anymore. It just shows Gmail, Gmail, Google.com.

Yes I can switch between accounts, but how can the addresses back?

2 I am in Apple/preferences/mail,contacts and calenders, I have my 3 addresses just showing as Gmail, Gmail, google.com

If I select them, I have Mail & Notes checked for all of them, but no Address Book icon.

3. The weirdest thing is that, in an inactive Yahoo account showing on the left, I DO have the contacts/Address Book icon together with the others.

Shoudn't the address book icon show in all accounts?

4As far as syncronisation, yes in all accounts in messages if I start typing an address, I do get it from the address book, but things look certainly messy