Does it look normal in Internet Explorer?

You might have visited this second article, but if not, it might be helpful: Fix problems that cause images to not show.

If images are missing then check that you aren't blocking images from some domains.

• Check the permissions for the domain in the current tab in "Tools > Page Info > Permissions"

• Check that images are enabled: Tools > Options > Content: [X] Load images automatically
• Check the exceptions in "Tools > Options > Content: Load Images > Exceptions"

• Check the "Tools > Page Info > Media" tab for blocked images (scroll through all the images with the cursor Down 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.

Make sure that you do not block third-party images, the permissions.default.image pref should be 1.

There are also extensions like Adblock Plus (Tools > Add-ons > Extensions) and security software (firewall, anti-virus) that can block images and other content.

See also:

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• http://kb.mozillazine.org/Images_or_animations_do_not_load

Yes they appear when using Windows Explorer. I just tested on a coworkers computer.

I've done everything in the bulleted list in your answer and all was OK.

Where exactly do I check this? Make sure that you do not block third-party images, the permissions.default.image pref should be 1.

I don't have AdBlock plus and no firewall. Just standard ani-virus McAfee

Icons show fine in Internet Explorer.

Here is a screen shot showing the page with no icons and Firebug showing no errors.

My webmaster looked at the code for the icons and says it seems to be coded for Windows Explorer 8 and perhaps Firefox can not read it properly?

I fixed it. In Firefox Tools Options Content Fonts & Colors Advanced check Allow pages to choose their own fonts

Ah... Some "icons" actually are characters in a custom font. I'm glad you thought of that because it didn't cross my mind before.