Why does that happen? What adjustments can I make so it does not happen & I can see the pictures? Its not all of the time, just some.?

sometimes the document u r downloading is not working properly, or u r using an old version of reader. u on adobe reader 7.0? and sometimes the website is old and they have removed the content, but left the link for when they rebuild it with new info.

It usually means the computer hosting the images is down.

Your browser may be set to time out too quick to allow the images to finish downloading.

Your ISP may be blocking the images for security reasons.

Occasionally, it means the user who posted the web page either forgot to make the images public, or used an absolute address only his computer can find.

Another possibliity is a host computer so overloaded that it decided not to send the images, in order to maximize throughput.

In the case of eBay, often the seller lists more items than he has space for storing images on his hosting site. In that case, he often removes the images of cheaper items or items about to end.