In all webpages, including Firefox settings pages, text appears like poorly chosen Cleartype settings. This does NOT apply to the menu and Address bars, nor the drop down options in "Which topic best describes your question?" that appears when asking a question here. Troubleshooting mode does NOT solve this, however switching profiles DOES, so I imagine there is a setting responsible for this however I've reset all font-related settings I could find. I've attached a screenshot of the result on this page. Choosing alternative fonts does NOT solve this.