Being redirected from site...

I had another manager write me with this:

Is anyone having trouble with pop-ups and other issues on the board today?  I was in the middle of reading a post when all of a sudden, my pop-up blocker started going nuts blocking pop-ups, and then all of a sudden I got a blue screen and my entire computer just shut itself down.  I was pretty sure I hadn't clicked on any ads or anything on the side, but once I got restarted, I went back in to see if it would happen again.  This time, I again was in the middle of reading a different post when my internet navigated itself to a whole new website (an entry from yellowpages.com).  I've never had this issue before, and I'm on my work computer so I really don't do a ton of web surfing on other websites.

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Then another wrote this:
 

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I hadn't had issue with this until yesterday. at home, I had a couple times on the board where it would redirect to another page without me doing anything. I don't have specific examples of those, though, as I've forgotten what they were. I'm on FF3 on Vista at home.

Today whenever my ViewMark ad is for E U Search (or something like that), the page redirects from the board page to this page, in the same window, which shows up as a blank for me:

http://www.searcheworld.com/go.php?track_url=aHR0cDovL2MyMC52YWxhcnkuY29tL3BjbGljay52YWxhcnk/Yz0zNzg1MDE2My1hMDJiLTQ0MDQtODJiMy1iOGJlNDYwOTQ5NDE=&keyword=auto+insurances&bidvalue=0.0954&xmlprovider=valary&display_url=&action=redirected

I'm on FF3 on XP.

Any thoughts? Just seems odd that it would happen to all three of us, and that all three of us would have malware issues unless (is it possible?) one of the ads here is doing it.

If you need any further info from me, let me know!