OK -- Too bad for vision impaired users the 800x600 screen size is more readable. In the good ole days all browser based code was designed to this standard. Might I suggest you shorten this window from 650 to 600 OR add a scroll bar to accommodate this type user.
Second problem with the Imagegallery pop-up. I am using other than the default "~/uploads" as my image directory. Everything in the insertimage pop-up works as it should. Everything in the Imagegallery pop-up works as it should except the thumbnails are not displayed -- instead the pop-up shows the broken link icon and the alternate text. The alternate text is correct for the contents of the directory and if clicked the correct image is inserted into the page. This funny behavior started with 4.0.0.3 and is not apparent on your demo site -- only on my server. Has a new security parm been added for the thumbnails to be created in? How do I set this? Since the pop-up is a modal dialog I cannot see the pop-up source and discover why the thumbnail links are broken.