I've got the wp-database plugin installed, and the I've placed this onto my blog, however, MyPHPadmin says I need to drop the wpcomments table.
This case I get the infamous "Error connecting to database".
The second thing I've tried is creating a new database and uploading the wp-database from your online into this new database.
I get a white screen when I load it locally.
One of my mates is a database designer and he said ensure that the languages from the SQL is the same from your hosting to the local host. I'll give that a try.
I've also tried copying the entire online blog into localhost. And just says error connecting to the database.