I've been downloading mp4's no problem, but suddenly it's no longer working. What happens is that as it's completing the download, my computer elects to use a camera application to open the mp4, which cancels the download. I'm never given an opportunity to change the application I'd like to use to download the file. I'm sure in the past on this computer, somewhere, I selected to use Quicktime to open mp4's. But I can't for the life of me find that location, nor do I understand why it's changed. Can anyone help?