i was having the same problem as everyone else until yesterday and i thought it would be helpful, to at least one person, to share my solution. after two weeks with this problem i finally gave up and bought a galaxy rugby and it occured to me to try the rugbys battery on my s2(since they are the same size). this fixed the problem immidiately and whenever i put the original s2 battery back on the problem comes back. so it seems like the problem is with the battery. however, the batteries might be the same size but the specs(?) are not the same. the original s2 has a "3.7 V Li-ion BATTERY 6.11 Wh" and the rugby has a "3.7 V Li-ion BATTERY 5.55Wh". i dont know if this will cause long term consequences but it has fixed the problem.