Thanks Umalo... A good consideration, however, the textfield itself has no child elements, and the only element above it in zorder is the border (which includes the close button) and it is intact. Also, the "effect" scrolls with the text itself.
The apparition may just be an artifact left over from the resizing of the text itself, I am unsure. But there is no doubt that the apparition follows the line elements of the textfield when scrolling, which is yet another leading factor in the idea it is part of the text, and not another element. Of course... not a guarantee.
There are only 3 physical images involved... the border, the button, and the scrollbar + btns (cropped), everything else is either container, text, or preview pano background.
Still open for suggestions.