Oh Boy!!! I just connected mines with a wire, and it is absolutely crap too!!!! I'm assuming it has to do with the modem they give you. Try bridging it to a wireless router you have. I'm going to do that and comment back on how it goes.
Edit: So after bridging my router (which took like 2 hours because TW customer service is total crap), I still ended up with the same result. I don't know how to fix this issue!!!!