no offense, but I would throw down for a) a new monitor
or B) a new computer
Reason being, I have had friends, who, in the process of owning an HP vectra have had numerous monitor problems and end up exchanging them more than two or three times in just a few months. (usually under warranty) and the warranty will keep getting extended as long as you get a new monitor. Big hassle and waste of time if you ask me. Otherwise, make sure the port connection is tight and the connections are clean and you dont move the monitor to much. happy plugging!