What would be causing a high ref rate. Something has hit my FPS (60 -30 ballpark). I suspect a symptom of the cause is the "ref rate" since it is sapping the highest milliseconds.

ref = time for screen refresh and monitor sync (and for the 3D card to flush its command buffer)

I suppose I should start removing new things until it goes back up; however, could it be an external issue i.e. another app in the background?

Input appreciated.