Thank you for asking. A more serious problem has arisen first of all. The aforementioned MySQL errors, which I thought were just appearing on my WP login page are actually public on my homepage!
Any person visiting my site is seeing a string of errors (relating to real world login errors) at the top of the page, quite publicly, revealing delicate private login information.
Please advise how to remove and prevent this or to why it is happening?
As to your question.. A standard wp install hosted on a standard hosting service. What specifically do you need to know?