Last modified: 2011-04-14 15:14:19 UTC
Compare: http://en.wikipedia.org/w/index.php?title=Wikipedia:Sandbox&diff=prev&oldid=206801526 http://en.wikipedia.org/w/index.php?title=Wikipedia:Sandbox&diff=next&oldid=206801526 These should be symmetrical, but they are not. When deleting whitespace, the software collapses it and does not show it as a change. You may need to add .diffchange-inline { border: none; border-bottom: 1px solid #f00; } to your CSS to see the difference properly.
CC'ing Nikerabbit, who added the class.
I have no idea what has happened, there is no such class in example urls anymore.