random database error...
 

This is the error...

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Access denied for user '(edited)'@'localhost' (using password: YES) /home/(edited)/public_html/forums/includes/class_core.php on line 313

It happened suddenly, I don't understand the problem. I've edited nothing. No staff have.

It's telling you the password/username in the config.php are not working, for that to happen the password/user has one of 3 problems..
The password or username have been changed in the config.php or in the CPanel under mysql databases. (Unlikely in this case as nothing would work)
The permissions for that user are insufficient for the particular operation it was trying to carry out at the time.

It is strange that this has occurred suddenly, although you don't say what you were doing when you got the error.
If it is something that requires an entry deleted and you have not set the user up with the permission to delete items, it will still be able to write and fetch posts etc but not delete anything and this is the type of error you will get on the occasions when a deletion is called for.

These are the selections you can make when giving a user permissions in the DB.....
SELECT CREATE INSERT ALTER UPDATE DROP DELETE LOCK TABLES
INDEX REFERENCES CREATE TEMPORARY TABLES CREATE ROUTINE
EXECUTE
If you have left one that's needed occasionally unchecked when setting the user up, such as DELETE, you will get this error when the software is trying to delete a post or attachment.

There is no way to check which permissions have or have not been applied, the easiest fix is to check the username in your config.php file, close the board, remove the user and then put it back again with all the required permissions, then reopen the board.

--------------- Added [DATE]1290228408[/DATE] at [TIME]1290228408[/TIME] ---------------

I just tried to open your site and it is not accessing the DB at all, check your config.php and the user in the Cpanel/Mysql Databases.
Make sure the dbanme is correct in the conig.php as well.

The dbname and everything is correct, as I said it hasn't been altered at all as I'm the only one with access to the root files and MySQL etc.

Are you on a shared server?

VPS shared hosting.

Have you checked that MySQL itself is running properly?

Seems to be running fine.

Verify there are no extra spaces in the username, database or password field. Also double check that the info is correct.

Quintuple checked, even re-download/entered the values in the config file. I'm blank.

Means that there is to many connections to the database. Talk to your host about the connections.