A named IMG is set (eg document.picture.scr = x) in a cell in a fixed width table. The image is scaled to the largest image width that has been set before. If an image whose width is the full size of cell is set then the next image will scale properly. To see problem load attached html. Click second thumbnail then click first, notice scaling problem. Now click third thumbnail and again click first, no more scaling problem.
Created attachment 11115 [details] Bug test case
*** This bug has been marked as a duplicate of 9276 ***