As the title says, this has been an issue for a while, and I'm just getting around to posting about it. I figured I would help out and make the issue known. If you are in Gmail, using FireFox, and you click the paper clip icon to add an attachment to your email, while you are browsing through the window to select your attachment, if you press space-bar to preview the attachment (before you click add, while you're still browsing) and then you use the arrow keys to cycle through the list of items to preview whatever is next in the folder, FireFox will crash, without fail every-time. It's frustrating because usually when I'm attaching some images to an email I like to preview them before I attach them to make sure they are the correct one, and when I use the arrow keys to cycle through the previews, FireFox crashes. Just thought I'd make this known! :)