I have a 1987 cape cod style custom built home. I have owned it for about 3 years (first home). About a year or so ago I noticed that the paint in the corners on the west side of the 2nd story dormer (just on that one wall, does not go into the ceiling) is cracking. I picked some out and can see the corner joint underneath. I dont see any water damage. I did have new windows installed a few months back, but the problem was present prior to that. About 2 years ago I replaced some siding and that seems the be about when the problem surfaced.

When I was replacing the siding I used the window to enter and exit a lot. While painting I would stand in the frame and hang out the window. I also had a weight bench and 300 lbs of weight set up in the dormer (has since been moved)

Does it sound like the house is setteling or something a little more serious?

What is the best way to repair? Cauling or spackle?