I tried again and still down, I tried booking and it worked so I went back to modify and now it works. I got it all done..
Seems like DVC site is down every other day.
I have not (haven't tried), however there are times when the 2 Disneyland resorts are taken offline when Disneyland is making changes to their systems. DVC used to post notification of this but I think they've given up keeping us informed.