I checked the web page. It looks okay to me. What thumbnails are you having problems with?

Today I updated to the last version Firefox 36.0.4 but the problem exist, the thumbnails not appear.You can see attached picture

Missing icons are usually supplied by a font that is downloaded from the server (@font-face) as you might see by little boxes that show the hex code of the characters instead.

Make sure that you allow pages to choose their own fonts.

• Tools > Options > Content : Fonts & Colors > Advanced: [X] "Allow pages to choose their own fonts, instead of my selections above"

You can check the gfx.downloadable_fonts.enabled pref on the about:config page and make sure that it is set to true (if necessary double-click the line to toggle its value).

You can open the Web Console (Firefox/Tools > Web Developer). You can check the Net log and the Network log in the Web Console (Firefox/Tools > Web Developer) to see what content is blocked and has a zero file size.

• https://developer.mozilla.org/Tools/Network_Monitor
• https://developer.mozilla.org/Tools/Web_Console