Ok if you saw my other post all is not so well i guess....

Here is what I am seeing... main rotor cyclic control is fine, seems to work ok.
Tail rotor control works but every now and then i am seeing the heli do something odd like turn a quarter turn left, or later right etc.... trying to keep the nose straight for any length of time seems impossible.

I put in a battery today after my flights that i thought was near dead... disconnected the motors and check the outputs of the 4in1 with my multimeter. The main motor was showing 0 to 10 volts as i'd expect when i bring up throttle. The tail was also showing decent numbers bring it up and then left to right. I plugged the tail motor in and use the multimeter directly on the motor contacts...again it seemed and worked normally... 0 volts to make 2 volts with full right stick at mid throttle.

Any ideas? Is this maybe some sort of odd interference? Do I have a bad motor? Bad 4in1 or gyro? I'm pretty sure I tweaked the gyro right, the prop'l seems decent enough at least for the moments the thing is working... I lower the gain, I've seen real tail twitch when it was up too high, I don't think this is twitch like that from gain. Anything I can do to try to track this down? I can hover for a bit but the sporadic tail makes me think something is wrong. I'm flying in a lot by as school, don't think there are power lines too close but not sure. I'm tempted to try elsewhere in case it's interference...