See:

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

• 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

• 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.

Thanks cor-el but settings are all fine. I'll keep digging but appreciate your help. Cheers.

Did you see any grayed images in Tools > Page Info > Media ?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Also make sure that your security software (firewall) isn't blocking images.

Thanks again cor-el, good try but no success, I'm afraid. I'll keep at it. I don't believe in giving in! Cheers.