Ugh...sounds like watching a move at my in-laws. And they also keep their TV on factory settings so everything looks like a soap opera.
As far as the picture tilting again after adjusting it, I'm not sure why that would happen. I've got an old Trinitron CRT that I rigged up as an arcade monitor and it has a few geometry issues and just a bit of tilt that used to bother me some. But the only place I notice it is on startup when it shows the test grid pattern.