The bug hasn't been fixed satisfactorily, so my recommendation still stands - allow single player play in Showdowns.
To take that suggestion one step further: Why not just make Showdowns a single-play 18-hole tournament?
That way, you would not have to worry about your coin-room opponent quitting, or losing their connection and leaving you hanging. And if you happened to lose your connection, you could just come back in and start playing again where you left off, with your score to that point intact.
I guess I just don't get why Showdowns have to be held in coin rooms. Especially with so many problems with them that WGT just doesn't have the talent or the inclination to fix.