[Bug 12306] New: Firefox 3 beta shows one-pixel-high black line when rendering some images

http://bugs.winehq.org/show_bug.cgi?id=12306

Summary: Firefox 3 beta shows one-pixel-high black line when
                    rendering some images
           Product: Wine
           Version: CVS/GIT
          Platform: Other
               URL: http://www.mozilla.com/en-US/firefox/all-beta.html
        OS/Version: other
            Status: NEW
          Keywords: download
          Severity: normal
          Priority: P2
         Component: -unknown
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Visit http://winehq.org/ with firefox 3 beta 4.
Look at the Codeweavers image banner ad at the top.
The top line is drawn black.
This doesn't happen when opening it as 
its own page (http://winehq.org/images/bannerads/cw-ad06.png).
It gets worse if you scroll winehq.org up and down slowly;
every time any part of that image is redrawn, the first line
seems to be drawn black.  If you scroll by a single pixel
at a time, you get a completely black image.

I've seen similar things on other pages, and it can get
very distracting.