/*if the last 10 blocks are generated in 5 minutes, we tripple the difficulty of the average of the last 10 blocks*/
if(height>nNewRuleHeight && sum_last10_time <= 5*60)   
{ 
    arith_uint256 avg_last10_target;
    avg_last10_target = sum_last10_target/10;
    if(next_target > avg_last10_target/3)  next_target = avg_last10_target/3;   
}


New pow function will solve block time fluctuation. Thanks Devs.