Windows Vista Mail Contacts: "To:" or "CC:" does not show all contacts

Hi,

I just switched to Windows Vista and transferred all my Contacts
(several 100) from Outlook Express to the Windows Contacts.
When I want to create a Mail, I click on "New Mail", then on "To:" or
"CC:". Strangely, the dialog that opens shows only parts of my
contacts and without folders.
Where do these contacts come from and how can I teach Vista Mail to
use my Windows contacts?

Tnx very much

Karl