Version: (using KDE KDE 3.5.7) OS: Linux read an RSS feed with the akregator plugin in kontact, select an item of that feed and put your mouse over the title (white font, underlined, in a blueish box). as long as the mouse is over the title, the frames resize by 1-2 pixels. this does not happen when using akrgator in its stand-alone form.
I see this same frame-resizing as well, but only _sometimes_ (it goes back to normal when I close and reopen Kontact) and then for _all_ links in the article, including the title as you describe it.
I haven't been able to reproduce this anymore for quite a while now, maybe since updating to KDE 4.3.x. So I'm closing this report, and somebody can re-open it, if they can still reproduce it.