Hi
I also have this problem.
I am running Listmail on a Windows 2003 server with IIS6.
I created a blank database in mysql, and then logged into listmail using the "install" password. It attempted to create the tables, however errored with this:
Creating config database table lm_config - Inserting example config data.
**Error inserting example config data.
I added the recommended line to admin.php which did allow it to create the tables, however now I can't log in?? It accepts the password "install" as valid, but continues to ask for it.
I have also cleared all cookies as suggested above, but still the problem persists.
Please help!!