Did you check the image exceptions?

• A way to see which images are blocked is to click the favicon (How do I tell if my connection to a website is secure?) on the left end of the location bar.
• A click on the "More Information" button will open the Security tab of the "Page Info" window (also accessible via "Tools > Page Info").
• Go to the Media tab of the "Tools > Page Info" window.

• Select the first image link and scroll down though the list with the Down arrow key.
• If an image in the list is grayed and there is a check-mark in the box "Block Images from..." then remove that mark to unblock the images from that domain.

• You can see the permissions for the domain in the current tab in Tools > Page Info > Permissions
• You can see all image exceptions in Tools > Options > Content: Load Images > Exceptions

This just started happening to my wife on her MacBook Pro (OS X 10.7.3). Up until 3 days ago emails from BJ's.com and Zales.com were working fine but suddenly they stopped loading the stylesheets. When clicking on the "view in web browser" link the css still still not load. Both of these mail lists have their CSS files hosted at f.chtah.com. When attempting to open the stylesheet directly in the browser it returns a 400 error.

I have tested the emails in Chrome on her Mac and they work fine. I also tested the emails with Chrome and Firefox on my Windows computer. The emails display perfectly fine there too.

For some reason it's only Firefox on her Mac that is having issues. She was still on version 7 so I went ahead and updated FF to v12 and the problem persists.

Any ideas?

I figured it out. Clear your cookies. The company that hosts the images and the stylesheets updated their domain name- i figured this out in Chrome, it was showing a different URL for the css- http://ebm.cheetahmail.com

After all the cookies (Privacy Tab in preferences) and reloading the pages the images and stylesheets started working again.

I hope this helps other folks.