Shimmering display

[fantrace]

My display has recently started to shimmer/vibrate and it gets noticeably worse when the HD is working. Not sure if this is going to be the display card (Ati 9550), MB (Asrock P4VT8+) or Power Supply. Any suggestions on narrowing down the fault please?

 

[NorthernCross]

If you installed ati Catalyst or even updated to the newest drivers, then you have to check composite refresh rate box in the (DDC) vertical and horizontal refresh menu. This happened to me when I changed my Gecube ati x700 for an Asus EAX700 because of some incompability.