From ATAT: (
http://www.appleturns.com/)
"Whoops, looks like we may have spoken a smidge too soon when we said that Safari is all that and a bag of Baked Lays. True, it is a zippy little browser, and it's got a healthy dose of that Apple fit and finish we all know and love, but apparently there are a couple of bugs still crawling around under the hood. "Big deal," you say; "it's beta software, after all, and bugs come with the territory." Well, yeah, that's true-- but when a product hits the public beta stage, any "issues" still remaining are usually relatively small potatoes. We're going to go out on a limb and hazard a guess that very few of the 300,000 people who rushed to download what Steve Jobs called "a very solid beta" expected to have their home directories wiped clean just by option-clicking a link, as MacFixIt reports.
Then again, as long as it's the same very few who actually experienced the bug, there isn't a problem. MacFixIt has only two confirmed instances of an option-click download nuking a user's home directory, and since that breaks down to two in about 500,000 (or 0.0004%), yeah, we suppose that qualifies as "extremely rare." Still, any bug capable of sending your home directory-- including your entire iPhoto and iTunes libraries, everything on your Desktop, whatever else you've got stashed away in your Documents folders, etc.-- to the Great Data Beyond should rightfully give you a screaming case of the heebie-jeebies. Shades of the iTunes 2 installer which exterminated data with extreme prejudice, yeah?
...
The moral of the story, kiddies, is to remember that installing beta software should be undertaken with the same type of caution as befits the act of stuffing live wolverines down one's pants: there's always a possibility that you'll wind up losing it all. And heck, even if you shun pre-1.0 products as if they were lepers bearing vacation slides, you should still always keep your backups up to date, especially when installing new software; after all, that iTunes Installer of Doom wasn't beta, you know. Danger lurks around every corner! Run! RUN!!"
Gotta love ATAT.