Yeah, in Buttonz there is no flicker but you can tell its not synched with the refresh when a partial line is only visible. In Pacman, I redraw the whole sprite regardless of whether it needs it or not which amplifies the problem. Because its in interlace mode, you can see the individual vertical lines going through the sprite. The lcd screen is actually pretty slow, I have to add pauses after telling it to hide the screen, invert it, and scroll. In Tunnel, after telling it to scroll, it gets around to scrolling the screen halfway through drawing the sprite which causes ghosting. I haven't really tested it out yet, but I have found some interesting registers. I'm hoping that one is for refresh and maybe one to let me know when a command such as scroll has executed.
