Awhile ago some of our customers contacted our technical support and reported the problem with BitmapViewer control (Graphics Mill 4.5 and earlier, both AJAX and Web controls).
The problem was in that BitmapViewer did not display images on production sites but worked normally on development environment. If you tried to download one of these images manually from site, it gave error 404.
Yesterday we duplicated the issue. The key condition to get this problem was to use publish feature of Visual Studio. If you post your web site manually, it works fine.
Now we try to solve the problem and we do our best to include the update into the next release Graphics Mill. At this time the workaround is available with the current version of Graphics Mill (4.5 or earlier). For more information you can read in our Graphics Mill FAQ.