Sorry about that, an update to the site this morning broke the database login. I'm trying to get it sorted out properly, but for the time being I've got a workaround in place that is handling it fine.
UPDATE: I've now found out why this happened, and the workaround is the only solution I've got
I needed PHP5.2 or higher running for stuff for the new site, and so upgraded using the only version I could find for this old OS, unfortunately this was compiled against an older database client API version which broke the database connectivity. I can't have both the current db client API and PHP 5.2 without upgrading the entire server OS, so for now it'll have to run the way it is - at least it's working, so it's not all bad news.