php - Warning: mysql_select_db() Access denied for user ''@'localhost' (using password: NO)

I am fairly new to web dev and I am in need of help trying
to find out what the problem is. I had an install of MySQL 5.6.10 and I was given a task
to update the src of a website that is currently live for past 5 years. None of the code
has changed and it works for the other devs local machine. The server is running 5.0.51b
and I just downgraded to 5.5.30 trying to get a syntax error to go away. The error was
the SET OPTION SQL_BIG_SELECTS=1 was deprecated to SET SQL_BIG_SELECTS in a certain
version. I am unable to change the syntax due to the version the server runs. So I chose
to down version to 5.5.30.

My problem after the down grade
is:

Warning: mysql_select_db()
            [function.mysql-select-db]: Access denied for user
''@'localhost' (using
            password: NO) in C:\Program Files (x86)\Apache
            Software
Foundation\Apache2.2\htdocs\****\src\www\include\func\func.db.php on
            line 47

I use MySQL Workbench for
my connections none of the connections or users have passwords associated with them. I
have another project that is not live that works fine from the localhost. My vhost and
host files all have the proper syntax for this to work (verified with the other
project). This all worked properly and was able to bring up the pages through vhost just
fine yesterday. I never had any issues with how it was all setup to pull the index page.
The only problem was the MySQL version issues. What can I do to fix this problem? I have
tried recreating connections in the workbench and even deleting all the instances and
recreating them. I am stumped. Any help would be greatly appreciated.