Myself and visitors that visit my gallery (http://www.stacyk.org/images) are unable to view a higher resolution of the picture. The "normal picture" shows up however, when you try to click for the larger resolution "actual picture" it does not open up.
For example see: http://www.stacyk.org/images/displayimage.php?album=728&pos=8
This image http://www.stacyk.org/images/albums/appearances/2009/0430catch/normal_8.jpg
Will not open up into the HQ version http://www.stacyk.org/images/albums/appearances/2009/0430catch/8.jpg
This might help: http://coppermine-gallery.net/demo/cpg14x/docs/faq.htm#noFullsizePopup (http://coppermine-gallery.net/demo/cpg14x/docs/faq.htm#noFullsizePopup) ;)