Help! Lost my start-up and shut-down screens!

[fvs]

I'm trying to customize the start up and shut down screen on my TomTom ONE 130 (using a MacBook). I replaced both "splash.bmp" and "antitheft.bmp" files with my own bmp files but now I have neither start up nor shut down screens!

Can anybody help?

Thanks, in advance!

edited to add: when I go into my TomTom directory and also via TomTom Home (Show Contents), I can see both files.