[Lazarus] Upgrading a project

[Koenraad Lelong]

Hi,

I have a project that builds fine with Lazarus 0.9.30.4. When I open it 
in Lazarus 1.0.4 I lose a TNotebook, and my project is "destroyed".
Is there a way to upgrade my project so I can compile it in newer 
versions of Lazarus ?
Are there any "best practices" to avoid such misfortunes in the future ?

Thanks.

Regards,

Koenraad Lelong