Connections loss while exporting/importing XMIfile

[Elior]

Hello,
I have a problem while exporting a project as XMI file and importing it to a new project. The connections between the classes doesn’t appear after importing the XMI file.
My project consists of several package controls, some of which are contain one in the other. The problem is that all the connection arrows between the classes does not appear after I import the XMI file to the new project.
Notice that when I export the XMI file from the deepest pachage control in the hierarchy the connection arrows do appears while importing the XMI file.
Thank you for your help.
Elior