I now have the D26 at 1673S. Tried 1693, it didn't work at all.
However i still (have never been able to, even on my previous computer/Pioneer 105) can not successfully use RW media of any kind. All I do is hang my computer and make a lot of coasters. R media works fine.
Re the 1693, I would probably attempt crossflashing, except I can not unpack .rar. I just don't understand it.