Right, your springs are out of balance. Once you pull them off the posts, my guess is that the spring ends are either not in the same holes under the pivot, or one of them is not in a hole at all, or a spring is broken. They should be pretty close spring force even before adjusting the balancing screws.
We assume the wheel is true, and the levers pivot freely. The Tektro service PDF shows the assembly:
http://www.tektro.com/04support/pdf/...20brakesC1.pdf