User Agent: Mozilla/5.0 (Windows NT 5.1; rv:9.0.1) Gecko/20100101 Firefox/9.0.1 Build ID: 20111220165912 Steps to reproduce: open the attachment with firefox(version 9，12,13 have been confirmed), two line are displayed. one is nearly horizontal. another is complete horizontal. cursor="crosshair" have been set for the two line. so when mouse move over the line, the curson will be change to crosshair. Actual results: but acctually, the first line is very hard to response to mouse pointer on some location of the line. but the secode line is easy on every location of the line. so i think the line is wide enough. maybe firefox has some problem on the situation. I have tested on IE9 and chrome, it works well. Expected results: the first line should be easy to responese to mouse pointer. that means curson should change to crosshair when the curson move over the line.

on firefox,only the line is nearly horizontal,the line is hard to interact with mouse pointer. but in other situation, it works well.