That's odd (perhaps);
It would be useful to know at exactly what point you got the error, and exactly what steps you had taken up to that point:
Did you get to do the wizard again? Or did you get the error straight away going to index.php ?
If you got the Wizard, what details did you manage to fill in (i.e. did you get to redo step 2 (of 4) i.e. to re-enter the database name, database usename, database user's password?
Please could you be exact - it sounds as though you didn't actually get to redo any of the Wizard!
I suspect that the path details have been entered into the database during a previous install, and as soon as the install references the database via the details you enter in the wizard, it reverts to using those (old & wrong) details.
If this is the case, you can either manually enter the correct details in your database (and WA_Globals.php file & globals.php file) or preferably to be sure, delete all the tables in the database, and do a clean (yet again) install.
Could Jimmy - if you are around - lend a hand, please?!