You want the latest version. The stability is fine once the upgrade is complete, it's the burning of the disk and the disk type that can cause problems. Most MK4's have dodgy DVD laser these days, so use a CD. Teh upgrade file is tiny so space is not a problem. There are some threads on burnign the CD. Essentially you need IMGBURN and to burn at the lowest speed supported by your burner (mine is 4x, although 1x is an option - here watch for ERRORS and WARNINGS during the burn process about the burn speed not being suportted). I think you need to inspect the setting s in IMGBURN for MODE2/FORM1, this is the case for MK3. a little light reading using the terms above and the search facility should clear up what to do.