It is possible that you clicked "Block Images" in the right-click context menu while saving an image.

See:

• http://kb.mozillazine.org/Images_or_animations_do_not_load

You can use these steps to check if images are blocked:

• Open the web page that has the images missing in a browser tab.
• Click the favicon (How do I tell if my connection to a website is secure?) on the left end of the location bar.

• Click the "More Information" button to open the "Page Info" window with the Security tab selected (also accessible via "Tools > Page Info").
• Go to the Media tab of the "Tools > Page Info" window.

• Select the first image link and scroll down through the list with the Down arrow key.
• If an image in the list is grayed and there is a check-mark in the box "Block Images from..." then remove that mark to unblock the images from that domain.

Thank you for your reply. Images are not blocked under page information.

Problem turned out to be choosing to "use system colors." When Firefox/tools/options/colors - use system colors UNselected, this oddball problem corrected. The problem was also related to disappearance of hot buttons on various sites, also corrected.

I do not have this non-appearing image problem on another laptop running XP with "use system colors" selected, and problem did not occur with Explorer on the affected machine, so seems to be Firefox 3.6 with Windows 7.