Odd behaviour with crtl-taste in KDE 3.5.0

Hi, I have encountered an odd phenomena with KDE 3.5.and SL 9.3 Pro. When I press crtl-taste in Konqueror (and maybe in KMail, too), several yellow boxes with one digit or alphabet in each appear. When I press the crtl once again, these boxes disappear. I have absolutely no idea what these boxes are supposed to mean. The only clue is, that these boxes seem to be related to the URLs in the active window... Any ideas? Can someone reproduce this behaviour? Thanks in advance! Kimmo