I used Barnarcle and tethered 8G a day on Atrix up until December 15, a jerk stole my phone in the party. Now I have Atrix 2, rooted easy, installed all tether apps easy, but can't get by AT&T warning "USB tethering validating..." and its block. It must has some hole when I install Barnarcle. Now I can't recall. You need to try shut off att network service while install, once you installed with it on, it seems all dead. Only people DOES it successfully, please answer. Thanks.