This one always catches me out and I find myself looking up the same thing time and time again. So for future reference I thought I’d make a note.
When you install Joomla there’s an setting check that lists any problems with your set-up that may effect the running of Joomla! In my case (both on 1&1 AND on MediaTemple) the Recommended Settings have flagged Display Errors as “On” when it should be set to “Off” – The solution is pretty simple.
Open the htaccess.txt file installed with Joomla! add:
php_flag display_errors “0”
save it to your server and rename it .htaccess