I just took the time to have a look at the original SVG, as posted at http://www.3111skyline.com/dl/dt/tde/img/tdeaccessibility/go.svg, and there's no artefact. I tried both 3.5.10 Konqueror and the corresponding version of Karbon14, and I can tell that it's not my revised SVG because I thickened up the T somewhat as Darrell requested at one point.
So the immediate questions are, Darrell, is this the faulty file, and does the artefact show up for you in Konqueror/Karbon, or is it only visible in the shutdown dialog?
The file linked above works fine here both as svg and svgz. I tested the svgz in my current GIT install by changing the icon theme to monochrome. The image rendered with no artefact in both the menu button and session exit dialog. Exited and restarted the session and there was no artefact.
Darrell