Nexus S (GT-I9020T), on T-mobile with the Unlimited Data plan. I've been using tethering with my laptop (Ubuntu 11.10, 12.04) for almost a year with this phone, carrier, and plan with no problems. However, the past two weeks, I've been having tethering problems for the first time ever.a Tethering now only works for about ten minutes, then gets cut off. Data/web works fine on my phone, but not on my laptop, even at the same time while tethered. Stopping and restarting tethering doesn't fix it either. So far when this happens I have to shutdown my computer and go find wifi to continue working, and try again in a day or two, but with same resuilts. Anyone have any clue what the problem could be? Also, two weekends ago, I hooked everything up as usual, but instead of the web I got redirected to T-mobile websites saying that I needed to upgrade to the Unlimited Data plan to tether. But I was already on that plan, and called T-mobile and got it sorted out. But when I call T-mobile support about this new problem, they say it's a phone issue and refer me to Samsung tech support. I'm suspicious though, since the tethering problem started right about when this mistake on T-mobile's side happened.