There's a plugin available for Firefox called Interclue, which allows a pop up preview to be seen if the mouse pointer is positioned over links on a web page. Basically it's a summary of the underlying link page, with screen shots etc. What i'm worried about is if these previews are the equivalent of a click if the link viewed is one from one of my own Adsense ads or links. If it is, obviously i'll avoid. Anyone know?
I wrote to the company, and they acknowledge that yes, there is a problem. They will work on a fix, but until that is announced, please don't install this plugin if you are a publisher, it could get you banned.