Error in two network scheduling

Hello, Experts

In project System, i am creating project with two or more networks within their respected WBS element.
I am giving following data in my project:

Project Definition:
           Start Date:1.4.2011
           Scheduling Scenario: Free scheduling
           Plan.meth/basic:Strict Bottom Up(Without Dates of higher level WBS)
           Plan.meth/fcst:Strict Bottom Up(Without Dates of higher level WBS)

Network 1:
           Start Date: 1.4.2011
           Scheduling Type: Forward
           Planning Type: Basic Dates 
           Schedule Automatic

Network 2:
           Start Date: 15.5.2013
           Scheduling Type: Forward
           Planning Type: Basic Dates
           Schedule Automatic

Now my query is:

                      When i save my project, Network 1 takes the project end date while Network 2 takes the project definitions start date and freeze that date in activites below Network 2. Some times Network 2 does not calculate end date from the duration given in the activity below that network.

Please Give me your suggestion to resolve this issue.......

Regards
Niki