Perhaps I'm not explaining it correctly...

have a look at the following three images...

The process I used to determine the colour of the surrounding pixels is a mid-way between the existing pixels, THEIR surrounding pixels, and the new one, to give the smoothed effect when zoomed out

Note that this is only a theory for windows font smoothing... I know that it happens like this in other smoothing situations, but I dont know whether it happens with windows font smoothing (but I'm not sure what other algorithm type they would use)
He's plotting the text in black (say) then again in white to try to erase it

Initial grid


Plot the text(/pixel) in black. The smoothing option changes surrounding pixels (anti-aliasing I think is the right word to use in this situation) to make it look better and smoother


Plot the text(/pixel) in background colour

Note that although the shade of the surrounding pixels has whitened further due to the new background colour pixel, their still just visible

The residue left over might cause the effect experienced by the reporter (a ghosting effect)

If that is the reason, then a box is the only real way to get rid of the text...