PP viewer doesn't show linked graphics to http:// address

[Esteban in Chicago]

I would like to somewhat protect the images from my presentations to by
inserting them into the presentation as linked images with an absolute
http:// address. I do not use FTP to link the images; I just type the whole
address in.

This seems to work when I open the presentation from PowerPoint authoring
program itself: when my internet connection is on, the presentation opens
with the graphics, and when it is off the presentation opens, but only with
place-holder boxes where the images should be. However, when I open the
presentations in the PowerPoint viewer, the viewer doesn't find the images.

I have several clients that don't have PowerPoint, but the PowerPoint viewer
seems to be useless to them as an alternative.

Any ideas?

Thanks!