For the icons above the preview window, yes. For the preview window itself, no, never have. Question was kind of vague -- hope I answered it, Grazie. ;-)
By the way, why is "you" in quotation marks? Am I not really me?
Are you getting them anywhere else in Vegas? In other programs? If the preview window is the only oddball, tried closing it (the preview window) and reopening it? I'm not sure why that would work, but worth a shot.