There seems to be some problem with the new (3.0.5) Monitor (Show Overview) page. Every now and then the new "white box" just keeps staying on the middle of the page and we get no Overview page at all. I think this started after upgrading to 3.0.5. It also looks like the Search function dies after a certain time has passed and the server has to be rebooted to get it working again.
I'm definitely seeing a pattern here (not just in ISPConfig servers.) It seems that there is a something wrong with PhpMyAdmin that causes a some kind of problem with MySQL that results in a system that can't restart in OpenVZ containers. Only hardware level reboot fixes this. After trying to restart MySQL service I got the Show Overview to show but it had this error message... After trying that OpenVZ control panel (Proxmox) shows this Syslog error message again and again... This has happened on several different MySQL servers now on different hardware. All Debian Squeeze OpenVZ containers.