https://bugzilla.mozilla.org/show_bug.cgi?id=63895
Ran in to this for the 2nd time recently. Is firefox the new browser to work around? It's been working properly in IE for years.
Clear example: http://jsfiddle.net/YjHaB/9/
How is it that some bugs go neglected for this long?
It is an open source project, so there is something that one can do about such things beyond complaining.