Quick update, in case any body else runs into this. After reinstalled deluge, it seemed to work, but disappeared again after a short time. No idea what triggered it. The unistall deluge app still showed up in my start menu, so ran that and then reinstalled from scratch. So far, this seems to have so...

Hey, I had something similar.... All of a sudden Deluge was no longer on my Windows box. I could reinstall, but it is now really slow in starting up. It takes minutes for the program to open after I select it.