There are a couple of probelms I can see:
1) The Insert record server behavior on the registration page is only set to store a value in the password column, it is not set to store anything in the username column
I think the cause for this is that you have selected the UserName column as the primary key column.
your table should have the following column at minimum:
UserID - Primary Key/Auto Number
UserName - text
userPassword - Text
when running the wizard, the UserID column should eb selected as the key column.
2) Password should be avoidde3d as a column name, it is a reserved word by the ODBC driver: