Attache your capx let me see it.... I would also recommend doing all tests in a browser with just interacting with the php files... so not using the game just going directly too http://www.yoursite.com/savescores.php? ... core=15000
if this does not work and you don't get a success message then something wrong with your php file... in that case suggest attaching your php file I will look at it... simply delete your username and password...
things too look for - most DB require a prefix to the table... so if the table is score the db would be prefix_score so just ensure your details for the db are correct sounds to me if your getting db error... your username, password or combination of both are not right...