Your CAD agents will open open corba threads w/ various CAD services at login. CAD Desktops must pull the other required CTI data from LDAP (CTI server location, port, CTI Manager Location, port, etc.) Once the login process in completed, the connection to LDAP is closed. A few things to check:
If 2 nics on Express server and VOIP Mon is not uses, disable 2nd nic in binding as 1st nic should be the data nic for which agents use to login, etc..
Verify the correct ip address of the LDAP/AD and compare to modify to: LDAP Server A= within the AdvancedManager.cfg and InstallManager.cfg.
Also, Check dsbrowser in editable mode for the site setup. Example:
1) C:\Program Files\Cisco\Desktop_Config\Util>dsbrowser /editable
2) Verify the Site configuration for LDAP configuration is correct.
-Good Luck...