User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a4pre) Gecko/20070411 Minefield/3.0a4pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a4pre) Gecko/20070411 Minefield/3.0a4pre I am using minefield trunk build and this problem exists for several monthes now (I upgrade almost every day) Looking on the title of each tab you can see a gray horizontal line connecting each two tabs titles at their bottom, there is no reasonable way to explain what is this line so I simple assume this is a bug. Reproducible: Always Steps to Reproduce: 1. Use minefield 2. open more than one tab 3. there you go Actual Results: annoying horizontal gray line using the default theme