DVD+R using dvd workshop
Grundig xenario 5100 stand alone

I have a menu with 8 titles, 4 windows on 2 rows.
If I play the dvd on the pc it works.
If I play it on my stand alone grundig player I can not select all the titles, example: If I select the first title and then I try to select the second one using the arrows of the remote-control the third or the fourth will be selected.
Maybe because of a critical distance between two titles to be sure that all the titles be recognized?