Yes,... the problem is really lack of resolution to draw the lines cleanly.
480i is really only 240 lines of resolution for each image. These are displayed 60 times per second alternating between upper and lower fields. (30 fps, 2 fields per frame = 60 fps)
a 480p display will update the entire 480 lines of resolution 60 times per second, so you will get twice the vertical resolution.
480i is really only 240 lines of resolution for each image. These are displayed 60 times per second alternating between upper and lower fields. (30 fps, 2 fields per frame = 60 fps)
a 480p display will update the entire 480 lines of resolution 60 times per second, so you will get twice the vertical resolution.