In every game if i try to run in Hercules mode (of course setting DOSBox to Hercules emulation), several vertical dotted lines appear on the screen like they were burnt into the monitor. The game itself runs well, and outputs graphic, but these vertical dotted lines annoy me. Is it a bug? (For example it appears at Stunts, but so far i experienced it with all the games supporting Hercules)

An other (not really important) flaw here is that QBasic can not detect it. When i try to call the Hercules mode there, it ends up in an error saying that it is not supported (it can not switch to VGA modes either, but this is not a surprise in Hercules mode...).