In March I updated my ATI Radeon HD5670 driver(s) to version 12.104.0.0 and since then the line-colours are fluctuating from normal to dark (faint on sheet and prints) on various random spots.  This effect is in particular visible on zooming. Somewhere - I cannot retrace the source - here on the site I learned that after updating one's drivers re-installing DS might be a necessity. So I did, but no improvement. It is striking that the previewed print shows the ffect where the print itself is o.k. See the enclosed pdf-print.

Since March is too far back I'm not able to return to that very event.

What can be the solution ?