Thumbnail from gif not displayed - convert to png?

[trodas]

When searching into PCMark scores with my CPU, I stumbled upon this score:

http://hwbot.org/submission/590463_joe_cool_pcmark_2004_core_2_x6800_%282.93ghz%29_10191_marks

 

The thumbnail does not work. So either make gif thumbnails working, or convert all gif images into png

 

Either way, the thumbnail should be visible. The picture works well, when clicked on the link "PCMark 2004 screenshot" in the box...