User Agent: Mozilla/5.0 (Windows NT 6.0; rv:10.0.2) Gecko/20100101 Firefox/10.0.2 Build ID: 20120215223356 Steps to reproduce: I used a mouseover event handler on SVG lines to show a self made context menu. Actual results: This works for nearly horizontal lines only until Firefox 3.6, probably not in Firefox 4, and surely not in later versions. Only on some few points of a nearly horizontal line, the context menu is shown. On all (or nearly all, I have not extensively tested it) other lines (that are not nearly horizontal), also on exactly horizontal lines, the context menu works correctly as in FF 3.6. When I change the nearly horizontal lines to a greater width (approx. 2 times as before), it's the same thing as before. It seems not to depend on the line width. You can prove this error in the upper right window of the program window started by the site http://www.constructor.valvegear.de/start.php?webfile=xtern.vgc.valvegear.de/webfiles/webfile1.vgc Expected results: ??? The problem does only appear in a FF later than 3.6. So what should have happened? A newer Firefox should behave just like an older one in this basic case...

@Robert L.: Yes, it seems to be the same effect as in bug 676001! --- Comment #1 from Robert Longson <longsonr@gmail.com> 2012-02-23 07:17:13 PST --- Is this bug 676001?