Encore : Buttons aren’t highlighting

I'm not sure if I should post this under the Premiere Pro community but there isn't an Encore community to post to. Just finished up a project and trying to make a DVD menu on encore and come across a problem I never have had before. My last 3 buttons won't highlight. I linked the files to them and made them buttons and checked everything I knew quite a few times and I'm stumpt. I wonder if it's because it's the first time I've done a big project before I have a total of 21 buttons on the menu. 20 chapters and 1 back button so is it possible I just have to many buttons on one menu? I wouldn't think it was the problem but it's my last 3 buttons chapter 19 and 20 and the back buttons that won't highlight in the preview so makes me wonder if that's the problem maybe after 18 you can't put anymore? Like I said I never seen this before and have done a few DVD menus before. Any suggestions of what it could be?