Encore preview is not a reliable indicator. Only viewing your burned disk will show you what you have - and the results may vary by player.
Encore will show a brief lap, even when it is not present when viewed on computer - I consider Total Media Theater (now version 6) the best emulator for DVD player playback - but not for such lags, since computer hard drive will not show what the seek times may be for a DVD disk on a DVD player.
I see we don't actually know: DVD or Bluray?