slide title wont appear in the menu bar.

I am have created a lesson in SL2 that comprises of multiple slides. I am having 2 issues as follows:

1- In the story view the thumbnails of slides are horizontally miles apart. I can't understand why this is so. Please see the attachment titled, "10 miles apart"

2- The second issue is that, while most of the activities in the scene are freeform graded ones, there is one in the middle (number 1.5 Flying Creatures 1) which is a non graded activity. For some reason it does not appear in the player menu. Can anyone explain why a slide wont appear in the menu? Please refer to the attachment missing slide. You can see Flying Creatures 2-5 but Flying Creatures 1 is missing.  

Thanks.