You just have to refresh the page, or it could be due to one of the function of "activate X-object" who isnt set properly, or even your firewall or other security system installed on your computer that block adds and banners from showing, if those contain traces of cookies, or spies, to prevent them from logging themselves into your computer, and from being able to identify your computer.
Microsft also have that one on Outlook Express, where you first have to clic on a security banner, on top of each email, to give it the required authorisation to show all, including pictures.
It is through the pictures that the cookie stuff are hidden and that they can identify your computer and know if you watched their email and adds or not, and send you more, if its advertising or similar news type.
We are simply registered via the images.
Thats why it could well be a security protection your computer have.
This or your VGA is defect.
if this is happening on websites where you usualy was able to see the pictures, then it could be that those, if part of an add or a banner, have been infected by a troyan or malware, that is already known and that your security system, or microsoft security system, can identify and therefor can stop.
It could also be that it has a "similar pattern" of a malware even it isnt, and therefor is automaticaly stopped.
If you have full trust in that website, you can remove your security system. If not, contact the webmaster of the site and alert him about the problem.
I hope this helped you Chris.