Mac OS binding to Samba PDC
Chapter 8 of Apple's Open Directory Admin 10.6 manual describes in great detail the operations you wish to complete. Also, skimming the table of contents for the word "bind" will also reveal information useful to you. Further, the dsconfigad man page will also help you accomplish your goal. There are easy instructions on how to use dsconfigad here. You can also achieve what you are attempting using the Directory Utility in your /Applications/Utilities folder. There are easy instructions on how to use the Directory Utility here, and it lists the prerequisites each Mac needs to bind to such a network. Also, flushing the DNS cache might do the trick: 

 dscacheutil -flushcache