I do have 3.1 in my 500 and it seems to work ok. I do have one issue though, after a Guru, it will not reboot. I have to do a CTRL A + A to force it. Other than that it works fine! Prepped the HD in 1.3 to begin though, not sure if that was the key... Try KS 1.3 to prep it, then swap ROMs.