This only started happening in Snow Leopard (10.6.1), as I had never once come across this issue when on Leopard. On occasion when downloading a file in Safari (4.0.3) I get the error "The operation couldn't be completed (SafariErrorDomain Error2)". This happens after the download finishes. It looks like it's trying to decompress a file, and fails giving this error. For example, I tried downloading Growl today and after it finished downloading, I got this error, but the file was sitting in the Downloads folder. So I try opening it and get "The following disks could not be opened: not recognized", so even the file itself becomes corrupt. It could also be related to TheUnarchiver I suppose, which I am also currently using (because the default archive utility in OS X is crap), but I had been using TheUnarchiver in Leopard for years and never saw this error in that situation, so I'm a bit stumped. Thoughts?