In some Firefox windows that should contain a video, I see an ominous red Do Not Enter icon and a suggestion that my Adobe Flash is out of date. So I go to the Firefox plug-ins window and am told that my Adobe Flash is up-to-date, but my QuickTime is dangerously (red!) out of date. So I go to Apple, which tells me that QuickTime is included in OS X and does not need to be updated. I downloaded the latest version of Firefox (34.0.5), tried to drag it into my Applications folder as advised, and was told there was a "newer" version of Firefox already there -- it was 33.1.1, which looks older to my eye. So I dragged that to the trash and installed 34.0.5 which is running now. So, uh, what should I do?