RE: hobbico mkII and li-poly?
Based on your motor and current, I dont see a clear problem. I used the A drive w/10x4.7 for hundreds of flights on the 2S 730 and 860 TP packs with no troubles. However, when I check my notes, the voltage was around 7.2v under load with the 860s on this motor @ around 2.0 amps.
I think you might want to try getting the pack warmer before using it. Try charging and checking current in the house. Also, try running the motor at full throttle for 60-90 seconds to help "warm up" the pack.
Today in 45 degrees temps in Las Vegas, my ESC prematurely cut out on a 1320 mAh pack about 3 minutes in. The same pack on days 50 degrees and above would fly for an easy 15 minutes before cut off. When I checked the battery temp, it was still around 50 dergees. I took the meter out, checked it again and sure enough, the cold battery was delivering less than 6v under load (2s pack). I took the pack inside the shop, warmed it up to 72 and ran the motor inside for 6 minutes straight with no cut off.
If warming the pack up doesnt help, let us know!