That's an unusual problem. It looks like something is botched in the site-image loading process with your Internet browser. I have a couple of suggestions which may fix your problem:
1.) I see that you also have Norton Internet Security (from your system tray in the lower right corner). You might want to check the settings there as well and make sure if any "Anti-Phishing" feature is enabled or not. Some anti-phishing software (particularly Norton ::) ) think that Proboards forums are phishing sites, when it isn't at all. ::) Make sure that any proboards.com related URL isn't being blocked.
2.) Make sure the Content Advisor feature is not enabled. You can check for this by going to Control Panel -> Network and Internet Connections -> Internet Options. Click on the Content tab and you'll see the Content Advisor feature. If the "Enable" button is greyed out, it means it's been enabled. Select the Settings button and Disable the Content Advisor feature, if you can.
3.) If you haven't cleaned out your Internet History cache, you should probably try that. You can do this by going to Control Panel -> Network and Internet Connections -> Internet Options. In there, there are options to clear your Internet cache.
If these options don't work, you could try a different browser to get around the issue, but this really shouldn't have to be the case, since others have reported that YC works perfectly under IE 6/7, Firefox, Safari, and other Internet browsers. In any case, here are some options:
1.) Upgrade to Microsoft Internet Explorer 7 - This is a new version of Internet Explorer that was recently released by Microsoft. There have been many changes, such as a new GUI, tabbed-browsing (copied from Mozilla Firefox
), better security features, and more. It may or may not fix your current problem, but it is a worthwhile upgrade. You can grab it here:
http://www.microsoft.com/windows/ie/default.mspx?mg_ID=10010
2.) Use a different Internet browser, such as Mozilla Firefox 2 or Opera. - You can try a different browser, like the ever-popular Mozilla Firefox 2, which is considered to be much more secure than Internet Explorer 6/7. It only takes less than 5 minutes to setup and use. You can find it here:
http://www.mozilla.com/en-US/ I highly recommend using Firefox over IE, since you are much less likely to pick up spam and spyware while browsing (much of these rogue software use the well-known security holes in Internet Explorer to install rogue software on your computer).
I must admit though, since you said not to ask you what was wrong, I'm a bit curious. 
Don't forget about the tabbed browsing features, as that's one definate highlights of Firefox. 
