Stefan,

As a follow-on to my last post...  it was not the jpegs directly causing the problem. After about 18 images displayed, viewer.ImageViewer started hanging. I added into the script a line to delete the ImageViewer object after closing the window (clicking "X") and the script kept on going to finish. Seems to me like the ImageViewer objects do not completely go away after closing and at some point a memory limit -- or number of allowed ImageViewer objects -- is reached. Any thoughts?

Steven