i have two computers in bdc/pdc config.
first problem i have is when i create a user and try to log on as that user i get a massage " the local policy of that machine does not allow it to logon interactively"
also the user that i created in the pdc is "unknown" to the bdc under user profiles.

From the error you are describing it sounds as though you are trying to log into the server with the new user's logon that you created. That cannot be done if the user does not have enough access. You will need to test the new account on a client workstation. Also, the bdc may not recognize the new account if you did not either give it time to replicate, or manually replicate the servers.

The "local policy of that machine does not allow it to logon interactively" message can be solved as follows:
Open User Manager for Domains, open the Policies menu and select User Rights. From the right drop down list box select "Log on Locally", click add, in the Names box select the new user or the to solve the problem permanently,the Everyone group,click OK...