Can only connect to Google....

I recieved a call from a rather annoyed client (not due to something I did), who informed me that for about 2 weeks his internet has been running slower and slower, until it finally will not connect. I went in and found that while I can connect to google (although I must open a new tab to do so, I cannot type in a new URL to a tab that has already had one), and google search executes almost instantly, but I am unable to navigate to any other site, via link or manually typed.

I verified connection via the ping command in console: Google, Bing, Whitehouse.gov, microsoft, Tom's Hardware, all respond. AOL (the client's email) did not respond, but I cannot access ANY site other than google. I ran a Live Update and full system scan with Norton Internet Security (client's normal AV software). I'm due back at the client's office on Wed with a few parts to swap out in an attemt to fix the problem, but I was wondering if anyone had any theories as to what may be causing the issue.

Thanks,
Mike