Finally! It has been over a week since I could access this site from my home ISP. Everything looked ok on the traceroute except the very last IP would not respond. No email, no ftp, no web. In fact for all 800+ websites on the same hosted server, they were all unaccessible.
So today I narrowed it down to my router. For some reason my old Apple Airport Extreme blocked this one IP. I could access everything else that I tried. Once I reset it back to factory conditions and set it up as a new router then everything worked again. Not sure what caused it, so I'm not sure why this fixed it. I'll wait and see if it happens again.
Found a forum discussion from 2009 that explains the problem. https://discussions.apple.com/thread/1908377?start=0&tstart=0