web images not displaying in design mode

[Daniel]

I hope someone can help.
I use FrontPage to create the .htm for eBay auctions. In order for the
images to display correctly on eBay, I've always had to make sure the
properties for the image includes the full web address
(http://etc.com/etc/etc.jpg). This was never a problem as the image
displayed correctly in the design mode for many years.
Now something has happened. I place an image from my hard drive onto the
page I'm designing. I publish the page so the image goes to the server.
Then when I change the properties of the image to include the full web
address (so the page refers to the web image instead of my hard drive), I now
only get a "red X" instead of being able to see the image. If I switch to
"preview" mode, then the image is there no problem, but it makes it too
difficult to "design" when I can't see the image. What did I do or how can I
make FrontPage so the web image in design mode. Even if I grab an image from
any webpage and drop it into the design page, it will not show up unless I am
in "preview" mode.
Please help as I can't do a good design if I am unable to see the images I'm
designing around.