Wow, Firefox 3.6 is almost prehistoric, a bit like Internet Explorer 6... (only much better than IE6, though!)
Have you an enterprise constraint preventing from upgrades? FF is already at v.10, although the version numbering went a bit crazy, but by sticking to old versions, you loose a lot of recent improvements (CSS, HTML5 support, etc.).
Thanks for bringing this up. I've been able to replicate this issue with Firefox 3.6.28 on OS X 10.7. This is definitely good for the team to have filed so we know where we stand with each browser. I'll update this thread with any changes we make.