The "joys" of homeownership

We have drain backup issues. Every few months, our basement shower drain backs up and sends water out the bottom of the shower, under the walls and out into the basement. It also backs up into the shower. We had the shower replaced a year ago, and were told that was the root of our problems. That doesn't seem to be the case.
Funny I used the word root, because that seems to be exactly our problem. Anyone that has been to our house knows about the 2 large trees in front of the house. Well, it seems that the roots from one of those trees may be growing into our drain pipe by the street, causing occasional backups into the basement.
As beautiful as the trees is and a wonderful shade provider during that afternoon sun, it is starting to get very costly. And since the back ups happen on the weekends, we end up paying the plumber extra for the weekend call. That tree just may have to go.
Today our pipes had their 15 minutes of fame. The plumber came and sent a camera down our main drain in the basement bathroom. Everything appeared to be clear from our house to the street, but at the street is where the tree roots became visible. Upon the advise from the plumber, we called the city to see what they were going to do about it. They sent a crew out to open up the manhole cover and clear their MAIN pipe which runs down the middle of the street. I am told that everything is clear on their end. Then explain to me the video tape that I have showing tree roots growing into my pipe 44 feet from my house. Again, anyone that has been here knows that our house is not far from the street, so the problem would be in the street.
Well, if it is, we are still responsible because it may be in our lateral (whatever that means. That is what the city guy told me) The city is only responsible for the main line and we are responsible for anything else.
So, our pipes have been rotor-rooted, the main city pipe has been rotor-rooted. All we have to do now is wait a few more months to see if we can go swimming in the basement again. Stay tuned for the latest plumbing saga.