Safari uses a Google service to drive those warnings, so it makes sense that Safari and Chrome would be the two that are balking -- I believe it's the same database.
META: Malware warning
If you're on Safari, and you just want to disable the warning, go to Preferences -> Security and uncheck "Warn when visiting a fraudulent website".
People are correct to say that macs are theoretically vulnerable to viruses, but I am still unaware of a single case of malware downloading and installing itself on a mac without user interaction.
Plus, we mac folks have a hard edge. Just turn off the warning and let loose.
a real, honest-to-god malicious Mac OS X virus would be big, big news.
There is a way to clear Safari's "SafeBrowsing.db" cache using Terminal, but I think in this case it would not help -- Google is telling Safari that MGoBlog is a threat, and clearing the cache won't fix that.
I turned off the preference for now because Brian says the problem is fixed, and will try turning it back on in a week or so.
The app on the iPhone is still force closing.