Google redirects to Quantcast.com

Today I had a strange problem.
I was trying to open google.com from firefox. And firefox was redirecting me to Quantcast.com. Now I could open every other site but google.com.

And Internet Explorer was also working fine. It could open google.

I just cleared the 'Private Data' including 'Cache' in firefox, and it worked fine.

But as I was not able to reproduce it, I could not get the reason behind this strange behavior of firefox. Could this be a case of HTTP Response Splitting?