Usually if you are having problems with torque, a little right hand thrust will do the trick. As mentioned earlier, a couple of washers under the left side of the motor mount will usually get it. Another possibility is wing incidence. As you bank into a turn, the inside wing slows down. When you execute a slow turn, you have to compensate for the reduced lift with quite a bit of elevator. So you effectively have shorter wings (the "lifting" length of the wing is always measured parallel to the horizon) and a high angle of attack. If there is any warp or twist to the wing, or if the wing incidence is all-around too high you get into a tip stall. The inside wing tip is just flying too slowly for the high alpha. So, it loses lift first causing it to drop before the outside wing loses lift also. That sounds like what you were experiencing.
Finally, there is down thrust. With a "high lift wing", that is one that generates a lot of lift per inch, often the wing climbs so quickly that it leaves the tail behind. Imagine holding your airplane level by the wing balanced right at the center of gravity. Now imagine rapidly lifting it straight up twenty or thirty feet. The wind drag pushing on the top of the horizontal stabilizer would cause the tail to "weather-vane" down in relation to the wings. This is more or less what can happen with wings that lift efficiently at low speeds. Especially if the motor is really powerful. The fix is to add a couple of degrees of down thrust to the motor in the form of a couple of washers behind the top of the motor mount. That way, as the thrust and thereby speed and lift increase, the motor is effectively pulling the nose down even as the tail is trying to pull the nose up. Balance is good!
Why that matters in a turn not always obvious. But it gets back to the tip stall problem. If the plane has a tendency to pitch up, and the wing incidence is too high (or twisted), and there is no compensation for torque, you will have a perfect storm of conditions that combine to make flying no fun.
In short (too late!), if a plane won't behave its self, check wing incidence (angle of wing chord center-line relative to H-Stab center-line). 1 to 2 degrees is usually adequate. Then experiment with thrust angle. I find that with planes that are designed to glide well on little or no thrust, two washers behind the left upper corner (facing into the prop) of the motor mount, three or four under the upper right, two under the lower right and none under the lower left, often gives just the right balance of forces. the motor should be pointed to the right and down at the same time. You will have to experiment, its part of the fun.
Good luck!