A Kmail curiosity

Hi, Since I installed the Spamassassin, I've observed an interesting "phenomenon" : in the Main Toolbar of Kmail, the "What's this" icon (the most left one) moves to the right during the time I'm using Kmail. Notice that the icons immediately to its right, "Filter Classify as spam" and Filter Classify as NOR spam", where installed by Spamassssin. I've already tried to insert a "space" and a "line" between them (with Configure Toolbars), but the phenomenon remains. Any ideas or it's just a bug? Lívio