Sony DVD Architect 5.0 Pro problems with Next button on Remote for DVD.

Hello Everyone, I am new to this forum.
I have Sony DVD Architect Pro 5.0 version and I have been authoring DVDs since March. I have this problem that I am stuck with.

So basically the DVD has a menu with 6 videos and a link to sub menu 1 . The sub menu 1 contains 6 videos and a link to sub menu 2 with 2 videos. Each video is named Lesson 1 , Lesson 2 and so on.

I have done end action, menu navigation and everything that was necessary. After I insert the DVD in the player.

In the main menu I can play all the videos properly. While watching Lesson 1 if I press Next on the remote I can skip to Lesson 2 and same until Lesson 6.

Once I play Lesson 6 and try to skip to Lesson 7 (Lesson 7 which is in sub menu 1) using the "Next" Button it doesn't go to Lesson 7 but instead goes back to the main menu. I am having the same problem when I click "Next" to skip from Lesson 12 to Lesson 13 (Lesson 13 is in sub menu 3).

I am attaching 3 all the screen shots so you can understand better. I have been trying to find solution for this problem but I am unable to find anything.
Please help me out!

This is the main screen shot of how I have the menu's videos placed in Sony Architect Pro

https://dl.dropboxusercontent.com/u/20956345/New%20folder%20%2815%29/page1.jpg

These are the sub menu pages -
Sub menu 1

https://dl.dropboxusercontent.com/u/20956345/New%20folder%20%2815%29/energy2_submenu1.jpg

Sub menu 2

https://dl.dropboxusercontent.com/u/20956345/New%20folder%20%2815%29/energy2_submenu2.jpg

Please please help me out!
Thank you very much,
Romit