Create new MOSS masterpages
When you want to create a masterpage you should start with the Minimal.master page up on MSDN. It's a basic master page. It has everything you need in a masterpage, but no look and feel. You can then go and add everything you need. http://msdn2.microsoft.com/en-us/library/aa660698.aspx
You can also use the minimal masterpage created by Heather Solomon. He created this version because he ran into issues with the MSDN basic masterpage.