Problem of Thumbnail in Stumble or Dzone many more

hi friends
i need your help regarding a issue of thumbnail, i dont know why my thumbnail dont shown on stumble or dzone
kindly check this problem and try to find out …
for example
30 Extremely Majestic Waterfall Photographs Around The World - StumbleUpon
and at Dzone
25 Best Examples of illustration in Web Design

my website is
kindly check this plz guide me thanks

I find your pages are incredibly slow to load (and I can’t turn off those annoying video ads, either. Grrrr. :mad: )

Perhaps the bookmarking services time out when trying to grab a screen shot because they are having trouble accessing your pages. One of them seems to show an error page image. My browser keeps timing out when I try to open any of your articles.

thanks for replying
sir i removed the video and social bookmark buttons , can u check now!

here is screenshot of post page

can u send me your ip id, may be vps firewall disabled your IP for accessing my website , send me PM

Even i could not open your site. I had to use a proxy. Have u used a lot of flash content on the site? If yes, then that can be the issue with the thumbnail.

no i m not using any flash content, here is opening fine , i dont know, may be my vps have some firewall issue, it blocks many users IPs, they could not able to open my website
can u give me ur Ip, i can allow with WHM