User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b5) Gecko/20100101 Firefox/4.0b5 Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b5) Gecko/20100101 Firefox/4.0b5 I have Google Reader on my bookmarks toolbar as just an icon. Since installing the OS X Firefox 4 betas, when I click on the icon it grows way too big for the toolbar, stretching the whole thing. I will attach a screenshot. It does not happen every single time I click the icon, but about 75%. I have not been able to figure out the exact trigger. Reproducible: Sometimes Steps to Reproduce: 1. Log in to Google Reader 2. Drag from the URL bar to the bookmarks toolbar 3. Browse to another site 4. Click the bookmark you just created Actual Results: Large, distorted icon that resizes the entire toolbar Expected Results: Icon does not change This only happens on OS X. I have my profile synced with the new Firefox Sync feature and I have never seen it happen on Windows 7.

confirmed here - happens in a fresh profile too

this is no doubt linked to this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=464489