Shoutbox

I would imagine it's impossible if you've done an "unofficial" upgrade, as what that basically does is re-initialize the phones file system, and in the process erases the file allocator tables - ie the phone doesn't know where they're stored any more.

Also, as far as I'm aware, the contacts on the K800i are stored in the flash memory rather than the fs (which is what you are given access to when you plug it in via USB). This means that standard recovery tools such as R-Studio which Mike mentioned won't be of any help.

Let this be a lesson to you: Download MyPhoneExplorer and synchronise it all the time!