A little help with PSX back-up games

Hey, i recently backed up some of my old PSX games and would like to create back-up discs due to the original getting old and damaged and don't want to lose them.

Anyway, i burn the .cue and .bin files using ImgBurn and i burn at X1 speed, the game plays fine however there is a problem with the display, whereas it doesn't take up the whole screen, its almost shifted up a bit and theres a big black bar at the bottom, it easier if i draw it

----------------------------------------


< ------ game displayed here


----------------------------------------
< ----- Black bar at bottom of screen
----------------------------------------

its not like the picture is cut off, the whole screen is displayed, only its been shifted up and theres always a big black bar at the bottom

anyone know how to fix this, im assuming im doing something wrong during the burning process, wrong write speed maybe? im using CD-Rs, so wrong CDs maybe?

thanks in advance