The air.mozilla.org favicon doesn't display well in a number of environments. A good summary of how it looks on various platforms can be found here : http://realfavicongenerator.net/favicon_checker?site=air.mozilla.org&ignore_root_issues=on I'd recommend taking the source vector image for the two speech bubble icon for air mozilla and using the realfavicongenerator tool to generate a suite of scaled images and the html to bring our favicon into the 21st century.
Richard, Can you generate a big (e.g. 500x500px) PNG image of the logo and I'll update the favicons using that site above mentioned.
Created attachment 8749239 [details] [review] Link to Github pull-request: https://github.com/mozilla/airmozilla/pull/674
Commit pushed to master at https://github.com/mozilla/airmozilla https://github.com/mozilla/airmozilla/commit/dfd30750e51fcd1183ab94b7940fb0e3fcc804c9 fixes bug 1246287 - better favicons (#674)