It is just possible that you may have come across a Trojan.
From MacWorld Aug. 8, 2008:
Fake CNN news malware spreading fast
Over a thousand hacked sites are serving up
fake Flash Player software to users duped into clicking on links in mail that's part of a massive spam attack masquerading as CNN.com news notifications.
The bogus messages, which claim to be from the CNN.com news website, include links to what are supposedly the day's Top Ten news stories and Top Ten news video clips from the cable network. Clicking on any of those links, however, brings up a dialogue that says an incorrect version of Flash Player has been detected, and tells users they needed to update to a newer edition.
One distinguishing feature of the attack, Masiello added, is the endless loop it uses to frustrate victims. If user clicks "Cancel" in the dialogue that prompts for an update, another pop-up appears, said Masiello, that tells the victim that they have to download it to view the video. Clicking "Cancel" there returns the user to the first dialogue.
"It puts you in this perpetual loop, so your only options are to kill your browser session or be brow-beaten into installing it,"
Adobe is aware of the malware posing as its Flash Player, and on Monday warned users to ignore any updates that didn't originate on its own servers. "Do not download Flash Player from a site other than adobe.com," said David Lenoe, Adobe's product security program manager, in an entry on Adobe Product Security Incident Response Team's PSIRT blog. "This goes for any piece of software (Reader, Windows Media Player, QuickTime, etc.). If you get a notice to update, it's not a bad idea to go directly to the site of the software vendor and download the update directly from the source. If the download is from an unfamiliar URL or an IP address, you should be suspicious."
People who okayed the download of the bogus flash.exe file, said Danchev, instead received a Trojan horse -- identified by multiple names, including Cbeplay.a -- that in turn "phones home" to a malicious server to grab and install additional malware.
http://www.macworld.co.uk/news/index.cfm?email&NewsID=22323
If you have agreed to that installation, your system can be infected and your DNS settings altered, which results in your system using the wrong DNS servers, which can slow web surfing to a crawl.
This can be fixed by downloading and running a freeware utility called DNSChanger Removal Tool which you can download from here:
http://www.versiontracker.com/dyn/moreinfo/macosx/33696
Once you have run that utility you have to re-boot your Mac, then reset Safari, and re-enter your DNS settings in System Preferences/Network.
