While emulation may worsen the problem (if screen writes are not synchronized in any way with the screen refresh), I'd first and foremost blame the low-quality screen of Nspires. It's slow and it generates blurry ghosts behind moving objects, so it's probably a passive matrix. Passive matrices are cheaper than active matrices - and they accompany TI's goal of selling a locked-down model that does not (well, did not, but it took three years in the making) play games.
