The UnorthoBox Gaming Console works for me. I sent Esteban, my Sim, to Rattlesnake Juice in Oasis Springs, then used Buy mode to add the gaming console. I placed the console on the end table closest to the existing TV. Esteban was able to play Party Frenzy from the console, MySims Racing from the TV, Density Effect from the TV, and Multiplayer MySims Racing from the console with Lana McKinnon.
I couldn't duplicate your problem, so I don't think it's a game issue. I would suggest checking for updates to your mods if you're using any.
