Property Lines

Everyday it seems like there is something else wrong with this house. Now, the property line has just been resurveyed at the request of our neighbor--whom we have never met. It appears that were we thought we owned about 10 feet into the woods along our property line, the actual line is on the tree line. The line starts at the back of our property right where we thought it was but then comes closer and closer to our house as it comes toward the front of the property and the road. Hmm. We own none of the woods in the front yard on that side of the house. There are about 30 feet of trees separating our property from theirs and we were intending to clean up the line on our side but now I legally can do nothing with the overgrowth of weeds hanging on my line. Unfortunately, because of the convenants I also cannot put up a fence line to help confine the mess to what is now her yard. I can't even plant anything because of underground wires. There is now way to control what the lawn looks like 10 feet from my driveway and we own 4.6 acres. AHHHHHH - how frustrating. And if that weren't enough, the invisible fence line runs well inside the tree line -- obviously were the previous owners thought the property line was. So, now either we redo the invisible fence on that side ( a near impossibility ) or our dogs have a few feet of trespass onto her property. What a pain. I guess my biggest confusion is this: If you have 4.6 acres of land why would you knowingly/intentionally set your house ON the property line. In addition to that why is it that both the previous owners thought they owned part of those woods. Ok, I guess maybe it is time for us to have our own people come out and survey the property line.