This is a problem on the MarketWatch site - I see the same result in Firefox in Ubuntu. I sent an email to their feedback address, and will post here if / when they respond.

Same problem after the upgrade to Firefox 8 on Mint Linux.

Not only Marketwatch, but Briefing.com also. The problem appears to be recognizing the browser as residing in a mobile device. I suspect there will be a slew of websites which are responding to desktop Firefox with mobile web pages.

Marketwatch has corrected their problem and I'm waiting for a reply from briefing.com.

Not only marketwatch, but also Denny's and BigCharts.

My solution is as follows:

First type 'about:config" in the address bar...

then in the Filter bar type "user"

Now find "general.useragent.compatMode.firefox" and double click on it to change it to "true"

Now try the above sites.

Jerry