Well i'd gladly be corrected on this if i'm wrong but UnleashX cannot tell your games to run in progressive modes, the only thing you can tell UnleashX is to run itself in progressive modes. I wouldn't be so quick to shout bug as it infact isn't so clear as you make it out to be.
By the sound of it you are either trying to run a NTSC game in PAL or a PAL game in NTSC without your TV-set supporting it. Go into video settings and change your multi region settings to the video mode that's right for you. If the title isn't multi-region try pressing start button when the game is highlighted in the menu and try forcing it to launch in your video mode.
As far as progressive, i think it's only changeable through MS Dashboard.
Could also be that you've "bought" the wrong version, maybe the PAL BETA version from AOC group. Wichever the case is you should quickly forget about Driv3r since it's utterly rubbish.
Well try the Multi Region setting, that should do the trick.