All CMS items not displayed

[Casca2010]

Dear members,

I suddenly opened my forum and noticed that all the news item on the CMS Home page where gone! (see attached image).
All the items do appear if I go to ADMINCP -> Vbulletin CMS -> Content Manager.

Also, if I want to add a new article it also won't show up.
Pleas help me out,
Thanks in advance.

Edit:
I received the following email with a database error:

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Unknown MySQL server host 'db.mysite.com' (2)
/public/sites/www.mysite.com/includes/class_core.php on line 313

MySQL Error : 
Error Number : 
Request Date : Thursday, March 31st 2011 @ 11:36:59 PM
Error Date : Thursday, March 31st 2011 @ 11:37:09 PM
Script : http://www.mysite.com/ajax.php
Referrer : http://www.mysite.com/content.php
IP Address : 11.11.1.111
Username : 
Classname : vB_Database
MySQL Version :