I wasn't able to see the problem myself: on my Linux computer, the font looks the same in Firefox and Chrome. It would be great if you could report a bug in Bugzilla and attach a screenshot to it. You can use this form to report the bug.

If that's too much trouble, you could also just post a screenshot here in this forum and I can see if someone else can reproduce the bug and file a report.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

This bug is only happening in FF in Windows, on all win7 systems that I have access to. I have tested it without issue on Mac OS as well as in IE and Chrome. Loading the page in FF safe mode did not solve the issue. Here is a screenshot. http://img1.uploadscreenshot.com/images/orig/5/13401352127-orig.png

The letter S is the only letter that is distorted.

I will submit a bug report.

Other letters like the 'a' in 13px also look distorted.

Try:

• Anti-Aliasing Tuner: https://addons.mozilla.org/firefox/addon/anti-aliasing-tuner/

You can use this extension to see which fonts are used for selected text.

• fontinfo: https://addons.mozilla.org/firefox/addon/fontinfo/

Try to toggle some of the Boolean gfx and layers prefs on the about:config page to enable or disable some features.
Search: /gfx|layers/

• http://kb.mozillazine.org/about:config

As a web developer I am concerned that other FF users visiting our site will have this issue. This is what I would like to fix, rather than to tweak my own FF install to deal with the issue. I have filed a bug report and hope that this issue will be fixed.