The Split mode behaves a little oddly sometimes; it seems to vary with the structure of the original DVD. To see if everything else is working OK, try making the Split manually in Customize mode or try Main Movie and see if they produce a working copy. You can write the files to a hard disc folder and see if they will play on your PC before burning if you don't want to make another coaster. You might also try disabling PathPlayer and try Split mode again.