I think this is a feature request, not a bug... as I'm not sure this has ever worked;
But I think there would be a lot of benefit if sending a new tablenumber(x) message over an identchannel to a gentable widget would allow it to change which table it's displaying. Currently it only forces a refresh of the table that was already loaded.
This would means gentables could be made to display tables dynamically, and the tables wouldn't have to exist at i-time to be displayed to a widget!
I could send you an example showing this behavior not functioning if you'd like... it's written using all of my include files, but is pretty straight forward. Essentially tho, it boils down to this:
knum chnget "tablenum"
chnset sprintfk("tablenumber(%d)",knum), "graph1"