Interesting: The main tabs use the naming scheme from the demo (too lazy to change it, I guess), i.e.: "tab-1", "tab-2", etc.
I created the nested tabs using the naming scheme of "r1", r2", etc. Using this scheme was where the problem I outlined above occurred. When I changed the nested tab naming scheme to "r_one", "r_two", etc. the problem magically went away.