Arnold, if you are talking about the balloon that pops up when you put your mouse over the circle with the check mark in it then this thread should answer your question. The thread is from April '08 but I've looked through the SiteAdvisor options and there appears to have been no changes made since then. Is there a reason that you want to disable the balloon as it does disappear when you move your mouse away from it? It also has the X on it to close the balloon. I think it's there to give you a quick link to additional information about the site using the More info... link as well as the quick info on the site.
WilliamKidd, thanks for your reply. Yes, I meant the balloons. I followed the link you gave and read that it cannot be disabled, unfortunately.
My reason for wanting to disable the balloons is that I don't type blindly, and the balloons sometimes remove the focus from the edit box where I want to type. When googling, I will put the cursor in the search box, move my eyes to the keyboard and start typing. For unclear reasons a Siteadvisor balloon sometimes appears 'spontaneously' (perhaps because I move the cursor away over the green McAfee logo below the search box of the Google bar), with a small delay, removing the focus from the search box. So when ready with typing I discover that the search box is still empty. I admit it is my own clumsyness that I don't type blindly, but that's why I don't like the SiteAdvisor balloons.
And less important: in my opinion the balloons are too big, too obtrusive, too much clutter, and too self promotional. Most sites are ok; I would like Siteadvisor too be silent about them instead of those balloons.