Version: (using KDE KDE 3.3.2) OS: Linux Rendering images (digital photographs) can take several minutes already. These rendering times are doubled because the thumbnail generator thread is rendering the same image at the same time with the same process priority. Please lower the process priority of the thumbnail generating thread to cut rendering times.
Can you please confirm this is not happening with the document you tested KGhostView with and Okular?
Rendering times have been reduced to just a few seconds. And, the thumbnails appear after the main image has been rendered. Closing bug.