User & group authenticate

Hello,

we have configure our FileMaker Server on a Windows 2003 Server. The
Windows 2003 server is integrated in a domain.
Like describe in the FileMaker admin guide, we have set the Client
Authentication to "FileMaker and External Server accounts" and follow
all steps describe in the Answer ID 342 (Windows Authentication Methods
Used By FileMaker ..."
The authentication doesnt work on external account. What is strange
that the Security tab with the Client Authentication set to FileMaker
and External Server account don't give the possibility to set "Use
domain user accounts and groups" the radio button is not present ?!"

Please can you help me

Philippe Devaud