Hi George,
All I can say is, I hope you're wrong!
Several US sites that are actually selling the YPG-625 list the weight as 44 lbs. The one exception is musiciansbuy, who lists 39.6 lbs.
I can't pull up your link. It says I need latest version of Japanese something or other, which I have no idea how to get. Are they talking about DGX-620 specifically? All US sites taking orders call it YPG-625. Maybe there's a different machine selling in Japan.
I decided not to try the Casio/DGX combo, because it would have to go through the little Casio speakers, and they just don't cut it, IMHO.
Rick