Hi,
Make sure the window 9X box show up as a member of the domain in the PDC. Also, you might try adding the 9X username and password to the linux box. This would create a home directory for the 9X box on the linux computer complete with a .bash_profile env.
Also, you might consider renameing administrator to root on the PDC, and have the root Window password and the root Linux password the same. This is how I configured my NT PDC and Linux Box that joined the domain.