Parameters like Home Directory, HomeDir Drive, Logon Script, and Profile Path are typically set in smb.conf, but can be set per account with pdbedit. However, once a value is explicitly set for an account, it is not possible to remove this information from the passwd database, such that the value fromm smb.conf is used again.
This was already reported in
The proposed patch in this mail is probably a bad idea as empty values might make sense in certain situations.
Related to this, it would be great if the printed values of pdbedit output would be marked somehow if they are taken from smb.conf.
Too late for enhancements in 3.5. Raising version.