When you are installing the blogcomments on Brinkster take note:
Brinkster creates a db directory when you open an account. You need to upload blogcomments.mdb to that directory.
In constants.asp the LOCATION variable has to look like this:
Const LOCATION = "\{username}\db\blogcomment.mdb"
where you have to replace {username} with your own Brinkster username.
For more indepth technical information on this, read the database guide on Brinkster.com.