I have the same problem, and I've come to the understanding that it's the way the roads are and how sensitive Accords are to the slope of the road. I offer the following insight:
I move a lot. When I first got the car, I lived in Baltimore and Boston. In both places, the roads are sloped and the car exhibited this problem. And the problem showed itself more on certain roads. I was so frustrated since I had just bought the car.
Then, I moved to Southern California and had the car shipped there (where it NEVER rains and the roads aren't sloped). The steering wheel was dead straight ALL the time.
Eight months later, I moved back to Boston. I had the car shipped. The car is now doing the same thing, so I contend that it has to be the car's sensitivity to sloped roads in areas known to have heavy precipitation (rainfall, etc.).
In between all this, I never had a car alignment. I had a balancing done some time after I moved to CA.
